The Kavanagh Clan – A History

Kavanagh or Cavanaugh is one of the great names in Irish history. The clan strongholds were in Leinster. Several generations took the title of King of Leinster through the centuries.

Here are some of the family names of Kavanagh ancestry. Are you amongst them?

  • Kavanagh, Cavanaugh
  • Cavan, Caven, Keevan

This article will tell you about the exploits of Kavanagh warriors including the king of Leinster’s son who gave the clan its name.

But before we get to Domhnall Caomhánach, let’s start at the beginning of this story. That goes back a few generations to a clan known as Uí Cheinnsealaigh.

One branch would adopt the name of Kavanagh.

Diarmaid Mac Máel na mBó (d. 1072)

The Uí Cheinnsealaigh had their strongholds in southeast Leinster.

The lands were in what are now the counties of Wexford and Carlow. The territory spilled into parts of  Kilkenny, Laois, and Wicklow.

This clan had been dominant in previous centuries. But their powers had waned with the ascent of other Leinster clans. The Battle Of Clontarf changed the balance of power back in their favor.

One of their chieftains was known as Máel na mBó. “Mael” means bald and “bó” means cows. So, this moniker is “Baldy of the Cattle”.

His son was therefore Mac (son of) Máel na mBó. It was Diarmaid Mac Maol na mBó who expanded the clan’s power.

This Diarmaid became king of Leinster in 1032.  He also took the kingship of Viking Dublin. His territories expanded to the Isle of Man, with influence in Wales and West Scotland.

When King Harold of England was defeated by William the Conqueror, his sons fled for help to Diarmaid Mac Mael na mBo.

He was the most powerful King in Ireland of his time up until his death in battle in 1072.

Diarmaid Mac Murrough, King Of Leinster

Some consider Diarmad Mac Murrough (Mac Muchadha) was one of the great kings of Leinster. Some believe that he brought ruination to the island of Ireland.

Both positions could be true. Read on, and make up your own mind.

Diarmaid Mac Murrough was a great-grandson of Mac Maol na mBó. It was his older brother who was King of Leinster.

However, this brother died and Diarmad was elected king by the Leinster clans.

The High King of Ireland at the time was Turlough O’Connor. Worried about Diarmaid’s power, he sent his ally Tiernan O’Rourke to conquer Leinster.

O’Rourke was King of Breffni, which is what we know now as County Cavan and some lands in neighboring counties.

His forces used some savage tactics. He didn’t just raid the lands. His tactics included killing livestock to try to starve the local people.

But other Leinster clans came to Diarmaid’s aid. He drove O’Rourke away in 1132.

That started a period of twenty years of truce between the King of Leinster and the High King of Ireland.

Diarmaid Loses His Kingship

There were still many skirmishes and raids between kingships.

Diarmaid is said to have abducted the wife of his old foe, the King of Breffni. Some say she went willingly into refuge on Diarmaid’s lands.

By then, Turlough O’Connor’s son Rory was High King of Ireland. In 1166, Rory O’Connor used the abduction of Tiernan’s wife as a reason to march into Leinster.

The High King deposed Diarmaid from his kingship of Leinster.

Diarmaid Brings The First Norman Invasion Of Ireland

Diarmad fled to England and asked King Henry II for help. Henry permitted him to recruit Norman soldiers for his cause.

Fitzgerald and Fitzstephen were the first Norman lords to land with mercenary soldiers. Diarmaid had promised them territories in Wexford belonging to rival clans.

Fitzstephen laid siege to Wexford town in 1169. Wexford surrendered to Norman control after two days.

The two Norman half-brothers were followed by the Earl of Pembroke with even stronger forces. The Earl was Richard de Clare, later known as Strongbow.

Diarmaid gave his daughter Aoife in marriage to Strongbow. He also gave a promise that Strongbow was the heir to the kingship of Leinster.

Diarmaid Regains His Kingship

Rory O’Connor, the High King of Ireland,  marched his forces once again down to Leinster.

The Church mediated talks between Diarmaid and Rory. The outcome was that Diarmaid was restored as King of Leinster. In return, he agreed to recognize Rory as High King.

However, there was another part of the agreement. Rory insisted that Diarmaid send the Norman barons away from Ireland.

The main body of these mercenaries had arrived in 1169. It seems like Diarmad had no intention of halting Norman expansion into wider territories.

Diarmad was on a path to seize the position of High King.

Death of Diarmaid Mac Murrough

Before the mediation, Diarmaid’s youngest son was killed by Rory’s forces. He is said to have been heartbroken.

Although Diarmaid had regained the kingship of Leinster, he wasn’t to last long with the title, He died through illness in 1171.

Strongbow insisted that he was heir to the title and was now King Of Leinster. The other Norman barons continued to seize territories from other clans.

The second Anglo-Norman invasion of Ireland

King Henry II, the Norman king of England, was worried about Strongbow’s growing power.

Henry II invaded Ireland with a large force in the year of Diarmad’s death. Eventually, all the Irish kings gathered in Dublin to submit to his rule.

This was the start of the end of the clans of Ireland.

Domhnall Caomhánach, The First Kavanagh

The second son of Domhnall was called Éanna. He took his second name from the clan lands and was the original Kinsella. You can read more in our article about the Kinsella clan.

Another son took his second name from his foster family. The custom of the times was that children were fostered to other families within a clan.

Dohmnall, the eldest son of Diarmaid Mac Murrrough, was fostered at the monastery of St Caomhán (Kevan) in Gorey, County Wexford.

Caomhán was a popular moniker for Irish saints, with one expert counting fifteen saints with the name. It means “handsome” or “mild-mannered”.

Domhnall took the foster name as an adjective. Caomhánach means to be “like Caomhán”.

We’ve seen that Strongbow had married Diarmad Mac Murrough’s daughter Aoife. Strongbow made claims to be King of Leinster after the death of his father-in-law.

However, the Leinster clans later elected Domhnall Caombhánach as King of the province.

Domnhnall Caomhánach set out to organize support amongst the clans to go to war with the Normans.

He died in 1175. It’s assumed that this was an assassination arranged by his Norman enemies.

The line of Domnhnall Caomhánach line continued as the most powerful clan in Leinster for centuries. They claimed the kingship through to the end of the 16th century.

The Kavanagh clan went through centuries of conflict to hold onto their territories. The initial Norman threat was followed by English expansion through Leinster.

Art Mac Murragh Kavanagh (Art Óg Caomhánach)

Art Mór Caomhánach (old Art) was a Kavanagh chief who was taken into English custody in 1377. He died there in mysterious circumstances.

His son Art Óg (young Art) succeeded as chief of the clan. Art is also known as Art Mac Murrough Kavanagh.

He set about recapturing Caomhánach lands that had been taken by English settlers.

King Richard II of England set out to put a stop to resistance and raids by Irish clans. The King of England sailed into Waterford City in 1394 at the head of a massive army.

Art attacked and burned the town of New Ross in Wexford. But then, in a political gambit, he publicly submitted to the Crown.

King Richard went back to England, assuming that was the end of his Irish problems. But Art waged war once more in Leinster.

Battle Of Kellistown

Art Mac Murrough Kavanagh had the loyalty of the O’Byrnes and the O’Tooles. Their combined forces fought the Crown at the Battle of Kellistown in 1398.

(You can read more about the O’Byrne clan here).

They killed the Lord Lieutenant of Ireland, Roger Mortimer. As Richard II was childless, Mortimer was also heir to the throne of England.

In an extra twist, Mortimer was descended from a daughter of Diarmaid Mac Murrough. In other words, he was Art’s distant cousin.

Demise of King Richard II

Richard was incensed by these events. He sailed once more to Ireland in 1399 at the head of a massive army.

When the wily Art saw the size of Richard’s army, he switched to guerilla tactics. His forces used the mountains and the bogs to run raids and ambushes.

Supplies were slow to arrive for the English army. They eventually were facing starvation as well as guerrilla war.

Richard was forced to march them back to Dublin.

Meanwhile, Richard’s enemies in England seized advantage of his absence.

Henry Bolingbroke sailed his forces from France to England. The pretender to the throne found that much of the King’s armies were elsewhere!

When Bolingbroke overthrew Richard, he became King Henry IV.

Art Mac Murrough’s Triumph

Richard’s army in Ireland was a powerful force that included three Dukes and three Earls.

When they retreated back to Dublin, Art and his loyal clans harried and pursued them all the way.

It was a humiliation for a young English king.

But it was a triumph for Art Mac Murrough. He goes down in Irish history as defeating a King of England.

Art was the undisputed leader in the traditional Uí Cheinnsealaigh lands.

He continued to expand his territory until his death in 1417. It’s said that his death was by a poisoned chalice i.e. a poisoned cup of wine.

Domhnall Reagh And His Descendents

When Art died, the territories were split between two sons. Gerald took the lands in Wexford, while Domhnall took the lands in Carlow.

Gerald had a son named Domhnall Reagh who later became the chieftain of the Caomhánach Clan. The chieftainship remained in the line of Domhnall Reagh.

His son Art Bui became chief, as did his grandson Murtagh. However, they had to hold their lands through continuing resistance and war against English settlers.

These wars led to the deaths of Kavanagh chiefs. Cahir Carach Caomhánach was killed in 1538.  His son Donnchadh Caomhánach was killed in 1583.

Domhnall Spáinneach

One of Donnchadh’s sons traveled as a boy to Spain. This is how Domhnall Spáinneach (Donal of Spain) got his name.

When he returned to Ireland, he became an ally of Fiach McHugh O’Byrne a famous warring Leinster chieftain. (We cover Fiach in our article on the O’Byrne clan).

When Fiach McHugh died, Domhnall Spáinneach allied with Hugh O’Neill during the Nine Years War (1594 -1603).

But the loss at the Battle of Kinsale in 1601 was a disaster for Irish rebellion.

Domhnall yielded to the Crown after the Battle of Kinsale. In return, he kept his lands and died of old age.

Sir Morgan And Sons

Kavanagh rebellion didn’t stop with Domhnall Spáinneach. His son, Sir Morgan, continued to protect his territory.

Sir Morgan was a leader in the 1641 Rebellion. He was killed in battle during this rising.

His sons, Charles and Domhnall Óg (young Domhnall), continued the fight with their father’s armies.

Oliver Cromwell eventually quashed the rebellion in the 1650s. The brothers were imprisoned for a period.

Domhnall Óg followed his grandfather’s example and sailed for Spain. He joined the Spanish army to fight for a Catholic monarchy.

Charles stayed in Ireland and took up arms again for the Jacobite cause in 1689. He died in an explosion on a prison ship in 1691.

Sir Morgan and his sons were the last of the Caomhánach chieftains in Leinster.