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Notes on Castleknock, County Dublin

Young Cassidy. Illustration: Derry Dillon.

Located just inside Dublin city’s M50 motorway ring road, Castleknock is blessed with the magnificence of the Phoenix Park on its’ doorstep, as well as Farmleigh House, the official guest house of the Irish State, which was formerly one of the Dublin residences of the Guinness family.

Castleknock Lawn Tennis Club, on the Old Navan Road, is home to the largest tennis court in Ireland while St. Brigid’s GAA Club is one of the largest clubs in the country.

Castleknock and Luttrellstown Golf Club are also in the area.


Young Cassidy


John Ford, whose father came from County Galway, was one of the greatest directors of all time. The winner of four Academy Awards, his credits included Westerns such as The Searchers and The Man Who Shot Liberty Valance, as well as The Grapes of Wrath and The Quiet Man.

In 1964, Ford chose Castleknock as the location for Young Cassidy, a film set during the Dublin strike and lock out and based on the early life of the playwright and socialist Sean O’Casey. Australian actor Rod Taylor starred as Cassidy, with Julie Christieand Maggie Smith in support.

Much of the film was shot in this locality, including Donnelly’s Bar, aka the Railway Bar, on the site of the present-day Talbot Court estate off the old Navan Road.


Finn MacCool’s Father


Castleknock has been strategically desirable for a long time. Its Irish name Caisleán Cnucha recalls what is said to have been named for the foster mother of Conn of the Hundred Battles. According to the legends, Conn was High King of Ireland about 1,900 years ago.[1]

The mound beneath the Windmill Tower in the grounds of Castleknock College is supposed to mark the grave of Cumhall mac Trénmhoir, one of Conn’s warriors, who was killed after he abducted a druid’s daughter named Muirne. Cumhall and Muirne’s son Fionn mac Cumhaill, aka Finn MacCool, would become one of the most famous figures from Irish mythology.


The White Lady of Castleknock


The White Lady of Castleknock. Illustration: Derry Dillon.

One of the most notorious figures in Castleknock in the 14th century was John Tyrell, younger brother of Richard, 6th Baron Castleknock. He abducted Eibhleen O’Brinn, the beautiful daughter of Turlogh O’Brinn (O’Byrne), a Wicklow chief who lived near Ballyfermot Hill. Imprisoned in a turret of Castleknock Castle, she opened a vein with her breast-pin and had bled to death by the time her father and his allies had overpowered the castle and killed Tyrell. In the centuries that followed, many a tale was told of a ghostly woman in white who walked the castle walls at midnight ‘bright as a moonlight beam’ and wailed into the night sky.

An alternative version of this story places the event in the 16th century, with the villainous brother named as Roger Tyrell. However, if the last Baron of Castleknock died in 1370, then the John Tyrell version is the more likely candidate. In the latter version, Tyrell’s end is brought about when the head of the Knights of St John at Royal Hospital, Kilmainham, leads the attack to avenge the death of the young lady.

Eibhleen was also called “The Lady of the Castle.”

When distant chimes sound midnight hour,
The spirit pure is seen;
And moving round the lonely tower,
Looks bright as moonlight beam.

And as the moonbeams tint the walls,
And light the turret’s crest,
“Twas hence”, she says, “my spirit fled,
‘Tis here my bones find rest.”

“And here I wander, year by year,
For such my lot has been,
But soon at end my penance drear,
I’ll rest in joy unseen.”


The Crusader’s Castle


The once mighty Castleknock Castle, in the grounds of Castleknock College, was built for an Englishman named Hugh Tyrrel whose ancestor is said to have killed the English king, William Rufus.[2] He was with one of the first Anglo-Norman armies that came into Ireland and rose to become a trusted henchman of Hugh de Lacy, Earl of Meath, for which he was created Baron of Castleknock and given a 12,000 acre estate by de Lacy. He died in France in 1199, having served under Richard the Lionheart on the Third Crusade. The Tyrrel family remained in residence at the castle until 1370 when the 8th Baron, his wife and their only son died of the plague. [3]

In 1185, Hugh’s son Richard provided Benedictine monks from the Abbey of Little Malvern in Worcestershire with a grant to endow a religious house in Castleknock in honour of St Brigid. They founded a monastery beside St Brigid’s Well. The well is now located in an alcove on College Road, outside the boundary wall of St Brigid’s (Church of Ireland) church.


Poetry Versus Prose


Located just outside the gates to Phoenix Park, Bellevue Park was home to Alexander Ferrier, co-founder of  Ferrier & Pollock, once Dublin’s most famous wholesale silk and haberdashery firm. The Dublin writer Brendan Behan was once asked to define the difference between prose and poetry. He replied:

There was a young fellah named Rollocks,
Who worked for Ferrier Pollocks.
As he walked on the strand,
With his girl by the hand,
The tide came up to his ankle.

Now that’s prose” said Brendan, “if the tide had been in, it would have been poetry”.

According to a 2016 Fingal County Council Conservation Report on the History of The Site of Knockmaroon and Glenmaroon: Bellevue Park aka Parc, Knockmaroon, the house was demolished in the 1960s. Alexander Ferrier purchased Belvillee in 1831 and it was known from that point until its demolition as ‘Ferriers House’. See more notes on Ferrier here.


Samantha Power. Illustration: Derry Dillon


Local Heroes


Castleknock has no shortage of success stories in recent times. It was the childhood home of Pulitzer Prize-winning author Samantha Power, who excelled as a diplomat during Obama’s presidency and now heads up the US Agency for International Development, one of the largest official aid agencies in the world.[4]

The multi-award winning actor Colin Farrell was born and educated here.[5] Also born here were the Garrihy sisters, Aoibhín, Ailbhe and Doireann, who pioneered the concept of being social media influencers.[6] In 2005, their father Eugene Garrihy commanded a crew of nine amateur rowers who rowed a currach across the Irish Sea from Wales to Dublin, a distance of approximately 50 nautical miles, to raise money for the Irish Cancer Society’s Men’s Cancer Action campaign.

Famous for his blue eyes, the Hollywood star Aidan Quinn is the son of Ballina-born man Michael P. Quinn (1930-2019), a professor of English literature and poetry at Rock Valley College, Illinois, and his wife Teresa (née McCabe) from Birr, County Offaly. In his younger years, Aidan worked as a kitchen porter in Scotts (later Bradys) in Castleknock, and washed dishes and glasses at The Greyhound in Blanchardstown.


The German Jockey


In 1946, hundreds of German children were brought to Ireland in ‘Operation Shamrock,’ an Irish Red Cross to give them a sense of stability after the trauma of the Second World War. Among them was 11-year-old Wilf Berg from Cologne whose parents had both been killed in the war. He arrived in Ireland with all his worldly possessions inside a cigarette box and was taken in by a family who kept horses near Navan.

Wilf soon showed himself to be a brilliant jockey and became an apprentice at the Castleknock yard of trainer W.J. ‘Rasher’ Byrne, near where Castleknock Garden Centre once stood. He went on to be one of Ireland’s leading apprentices, racking up 130 wins by 1958. During the 1960s, he raced on tracks all over the world although his penchant for fast cars and faster women put paid to any substantial success. He subsequently returned to Germany where he was apparently killed in a car crash.

See more on Wilf Berg here.


The First Jump Scare


The first radio broadcast ever aimed at an Irish audience took place in Castleknock College. The event was a live concert transmitted from Paris on 5 April 1922. The hundred or so students and other interested amateurs were so quiet beforehand that one could literally hear a pin drop. When the music suddenly started, there were much jolting and astonishment from the audience.[7]




Knockmaroon was once home to Gilbert Burns who co-founded the Todd Burns’ department store on Mary Street, Dublin, in 1834 with his brother William Burns, Alexander Findlater and either William or Bruce Todd to. In 1856, Todd Burns supplied much of the platforms, seating, tablecloths and other furnishings used for the Crimean Banquet in the present-day CHQ Building. Gilbert and his wife Jemima, née Ferrier (1819-1906), either built or renovated a house just outside the gates of the Phoenix Park in Castleknock, called Knockmaroon Lodge. Knockmaroon (sometimes Glenmaroon) and Knockmaroon Lodge stood on either side of the main road and were joined by a Venetian-style bridge over the road down to Chapelizod. Gilbert died at Knockmaroon in 1881 and was buried in the Church of Ireland graveyard in Castleknock.


A Belt of Bridges


When the complex M50 Blanchardstown roundabout was built in the 1990s, a series of 18 bridges had to be constructed, along with an aqueduct and pipes, to carry existing works such as the Dublin-Sligo railway line, the Royal Canal and the Navan Road across the new M50 motorway.

Irish Precast concrete firm Shay Murtagh Precast based in County Westmeath supplied all of the 48,000m3 of precast concrete for these bridge structures including the innovative five-span viaduct bridge, designed by AtkinsRéalis, on the most difficult interchange at junction 6 where the M50 and the M3 meet at Blanchardstown.  This aqueduct carried the Royal Canal over the motorway.

Dermot Hanney was project manager of the overall Northern Cross Route, which involved the construction of 18 bridges. The new system opened in December 1996. According to Irish Independent of 6 December 1996, p. 41:

‘The building of the Northern Cross Route was undertaken in two phases. The first was the construction of the works at the Navan Road Interchange and the second was the rest of the motorway to the M1. A total of 330 acres had to be acquired for the project which has been on the drawing board for years but work actually began in January 1993. In total one million cubic metres of material was excavated which included 250,000 cubic metres of rock in the cuttings at the Navan Road interchange. Around 300,000 tonnes of macadams and asphalt were used in the actual road surface while approximately 50,000 metres of drainage pipes were laid along with 30,000 metres of various fences. That was before the construction of the 3km extension of the Northern Cross to Malahide.

Some 550,000 trees and shrubs are being planted in order to integrate the road both visually and physically with the surrounding, mainly rural, landscape. A badger sett at Abbotstown was successfully evacuated to an existing outlying sett prior to the commencement of the work. This was carried out by the Department of Zoology at UCD and Badger Watch Ireland in conjunction with the Parks Department.’

Jons Civil Engineering Company of Duleek, County Louth, headed up by John and Bernadette Pentony, won an award from the Irish Concrete Society in 1997 for their work on the project.

For more, or follow it on Google Map here. Or see the RTE film here.


The Railway Station


There are shades of ‘Beauvais – Paris’ with the name Castleknock railway station, which is actually in Blanchardstown. Just as confusingly, the old station – which had been around since the 1840s – was called Blanchardstown, but was in Castleknock! A small river forms the border between the two townlands. Between 1990 and 2000, the old station was upgraded to the present station, known locally as Laurel Lodge Station. It was upgraded again in 2012.


The Siege that Never Happened


A spurious tale is told that in 1642, the Earl of Ormond laid siege to Castleknock Castle with an army of 4,000 soldiers and 500 cavalry. In thhis tale, the castle was held by just 50 men under the command of a Lady de Lacy, whose husband was fighting with the Catholic Confederation, Ormond’s opponents, elsewhere in Ireland. When she realised the end was night, Lady de Lacy gathered all her clothes, money, jewels, and anything else of value into a pile and burned the lot, to avoid it falling into enemy hands. She then urged her men to fight until the death, which they did. She, the story runs, was the sole survivor. I actually had this story lined up for the Past Tracks panel, complete with a Lady de Lacy (who, with Derry Dillon’s artwork, looked suspiciously like my lovely mother-in-law). Fortunately, Castleknock historian Jim Lacey – who would have had a keen eye on Lacey lore – advised me Father MacNamara’s account was made up.  [8]




[1] Under the name Cnucha, the place is mentioned several times in the Annals of the Four Masters, Keating’s History of Ireland, and in several of the older Annals, both in reference to pre-Christian times and the earlier ages of Christianity. Here we are told, during the Milesian era, Conmhael of the race of Ebher defeated the descendants of Eremhon; later, it is described as the dumha (burial mound) of the sons of Eremhon, implying that it was a place of note and used as a residence. Conn of the Hundred Battles resided here; Feilim son of Conn is described as the brave King of Cnucha; a famous battle was fought here in the second century.  All these events are recounted more than once by the early Irish writers, and in an ancient poem as well as in the prose of the Dinn Sencbus which gives an account of the origin of the name.

[2] Castleknock Castle is a ruined Norman castle which was established by the Norman knight, Hugh Tyrell, who was later appointed as the first Baron of Castleknock, located on the grounds of present-day all-boys independent school Castleknock College.

[3] Hugh Tyrrell, 1st Baron of Castleknock (died 1199), was an Anglo-Norman nobleman and crusader who played a prominent part in the Norman invasion of Ireland. He was granted Castleknock in the 1170s by Hugh de Lacy, Lord of Meath. It is said Tyrell may have arrived in Ireland in 1171, as one of “De Lacy’s Knights” or right-hand man. He built Castleknock Castle. John Tryell, brother of Richard, the Sixth Baron, is said to have kidnapped the beautiful daughter of a Wicklow Chief (see “The White Lady of Castleknock”). It is recorded that the last of the Tyrell Barons was Robert (8th)  who, along with his wife Lady Scholastica Howth and their son and heir, died in 1370. The Book of Howth suggests they all died of the plague. Robert left his inheritance to his sisters Joan (aka Johanna) and Maud (aka Matilda).

[4] Samantha Power served as Obama’s US Ambassador to the United Nations from 2013 to 2017. She grew up in Castleknock before emigrating with her family to Pittsburgh, Pennsylvania.

[5] Double Golden Globe award winner for In Bruges (2009) and The Banshees of Inisherin (2023) plus Academy Award aka Oscar nominee for the latter Colin Farrell was born in Castleknock in 1976. He was educated at St. Brigid’s National School, followed by the exclusive all-boys private school Castleknock College, and then Gormanston College in County Meath. In 1993, after “giving it socks” on the dancefloor at Pods nightclub in Dublin, Louis Walsh asked him to audition for Boyzone but “he murdered Careless Whisper” so didn’t make the cut. However, the music world’s loss was to be the film world’s gain. He was inspired to try acting when Henry Thomas’ performance in E.T. the Extra-Terrestrial (1982) moved him to tears. He attended the Gaiety School of Acting, but dropped out when he was cast as Danny Byrne in the BBC drama Ballykissangel in 1998. As of January 2024, he has had 105 nominations for acting with an impressive 53 wins.

[6] Aoibhín, Ailbhe and Doireann Garrihy were born in Castleknock and are Irish social media influencers, having played different roles in the entertainment industry. Aoibhín is an actress, who played Neasa Dillon in RTÉ One’s Fair City from 2010 to 2013. She was a finalist in the first series of the Irish version of Dancing with the Stars in 2017. Ailbhe is a publicist and in 2018, she was a guest chef on TV3’s The Restaurant. She works for the family business. Doireann is a comedy impressionist and radio and television presenter, hosting the revival in 2018 of RTÉ Two’s The Podge and Rodge Show. In October 2022, she was announced as the new co-host of Dancing with the Stars alongside Jennifer Zamparelli.

[7] On 5th April 1922, Fr. John Ryan CM who taught at Blackrock College, organised the first radio broadcast specifically dedicated to an Irish audience which took place at Castleknock College when a concert was transmitted from Paris, France. The audience who had been so quiet you could hear a pin drop, were suddenly startled and astounded in equal measure. While the medium of radio developed quickly around the world, censorship rules in Ireland (and military disruption caused by the War of Independence and then the Civil War), stifled the development of radio broadcasting in Ireland. The ownership of transmitters was banned and amateurs operated in fear of arrest.

[8] This account is from a fictional letter written by an Irish officer to some friends in France, published in The Irish Ecclesiastical Record, Volume 7 (1871), p. 254-255.

“The Earl of Ormond, a Protestant, went forth from the city of Dublin on the 28th of last month at the head of 4,000-foot and 500 horse towards the county Meath.

“The next day he besieged with his army Castleknock, belonging to the Lady de Lacy, aunt of the Earl of Fingal. The husband of this lady was engaged in the army of the Catholics of Ireland. He left his wife in the Castle to keep it with fifty men only, being well assured that her courage was above her sex, in which he was not deceived ; for this lady, by the orders which she gave, caused 400 soldiers of the besiegers to be slain during the four days the siege lasted, and the number of dead would have been greater still, had not the ammunition failed, which this lady having perceived, she caused to be put in one heap all her clothes, money, jewels, and precious moveables, in a word, all that was found of any value within the enclosure of the Castle ; she then set fire thereto, so that there should remain no booty for the enemy. She also rendered useless all the arms which were in the place, having caused them to be broken, with the exception of those with which her soldiers were equipped, and in the light of the fire she harangued her soldiers thus:

” My faithful servants, you can well judge by the action I am after performing, what hope there is of favour from our enemies, and how little clemency I expect at their hands. I tell you, moreover, that you should not expect quarter from them, but remember the sentence which says, ‘ let the vanquished hope for nothing from their enemies.’ Take courage, then, and combat to death for the faith of your Redeemer ; you can never find a more glorious end, and the sooner to find it, go valiantly to attack the enemy of the Cross, lest, being made prisoners, any of you should, by bad treatment or the violence of torments, fail in the good resolution you have taken of dying to-day for the Catholic Faith ; in which I desire to set you the example by marching at your head.’

“This done, the besieged set fire to the Castle, and went down, sword in hand, with such resolution that, after a great carnage of their enemies, all that went forth remained dead on the field, with the exception of the lady, who was made prisoner by the Earl of Ormond.

“After this the Earl sent to Dublin for reinforcements, and pursued his march.”