By: HISTORY.com Editors

Brian, High King of Ireland, killed in victory over Vikings

Published: March 03, 2010Last Updated: May 28, 2025

Brian Boru, the high king of Ireland, is assassinated by a group of retreating Norsemen shortly after his Irish forces defeated them.

Brian, a clan prince, seized the throne of the southern Irish state of Dal Cais from its Eoghanacht rulers in 963. He subjugated all of Munster, extended his power over all of southern Ireland, and in 1002 became the high king of Ireland. Unlike previous high kings of Ireland, Brian resisted the rule of Ireland’s Norse invaders, and after further conquests his rule was acknowledged across most of Ireland. As his power increased, relations with the Norsemen on the Irish coast grew increasingly strained. In 1013, Sitric, king of the Dublin Norse, formed an alliance against Brian, featuring Viking warriors from Ireland, the Hebrides, the Orkneys, and Iceland, as well as soldiers of Brian’s native Irish enemies.

On April 23, 1014, Good Friday, forces under Brian’s son Murchad met and annihilated the Viking coalition at the Battle of Clontarf, near Dublin. After the battle, a small group of Norsemen, flying from their defeat, stumbled on Brian’s tent, overcame his bodyguards, and murdered the elderly king. Victory at Clontarf broke Norse power in Ireland forever, but Ireland largely fell into anarchy after the death of Brian.

How Scotland, Wales and Northern Ireland Became a Part of the U.K.

It’s a story of conquest and political union.

By: Becky Little

Timeline

Also on This Day in History

Discover more of the major events, famous births, notable deaths and everything else history-making that happened on April 23rd

1564

William Shakespeare born

According to tradition, the great English dramatist and poet William Shakespeare is born in Stratford-upon-Avon on April 23, 1564.

3:50m read

1778

John Paul Jones leads American raid on Whitehaven, England

At 3 a.m. on April 23, 1778, Commander John Paul Jones leads a small detachment of two boats from his ship, the USS Ranger, to raid the shallow port at Whitehaven, England, where, by his own account, 400 British merchant ships are anchored. Jones was hoping to reach the port at midnight when ebb tide […]

2:28m read

1791

James Buchanan is born

Future President James Buchanan is born in Cove Gap near Mercersburg, Pennsylvania, on April 23, 1791. Buchanan, remembered mostly for his administration’s corruption and his failure to solve the country’s crisis over slavery, also inspired salacious gossip about his love life over the course of his career. The son of wealthy Scottish and Irish immigrant […]

2:52m read

1865

“Panic has seized the country,” writes Confederate President Jefferson Davis

Confederate President Jefferson Davis writes to his wife, Varina, of the desperate situation facing the Confederates. “Panic has seized the country,” he wrote to his wife in Georgia. Davis was in Charlotte, North Carolina, on his flight away from Yankee troops. It was three weeks since Davis had fled the Confederate capital of Richmond, Virginia, […]

1902

Luis Castro becomes first Latin American athlete to play in the MLB

His opportunity came when a marquee player was pulled from the field due to a court injunction.

1915

Poet-soldier Rupert Brooke dies in Greece

On April 23, 1915, Rupert Brooke, a young scholar and poet serving as an officer in the British Royal Navy, dies of blood poisoning on a hospital ship anchored off the Greek island of Skyros, while awaiting deployment in the Allied invasion of the Gallipoli Peninsula. Brooke, born in 1887 in Rugby, Britain, attended King’s […]

2:30m read

1945

President Truman confronts Soviet Foreign Minister Vyacheslav Molotov

Less than two weeks after taking over as president after the death of Franklin D. Roosevelt, Harry S. Truman gives a tongue-lashing to Soviet Foreign Minister Vyacheslav Molotov. The incident indicated that Truman was determined to take a “tougher” stance with the Soviets than his predecessor had. When Roosevelt died of a massive stroke on […]

2:16m read

1954

Hank Aaron hits first home run of his MLB career

On April 23, 1954, Hank Aaron knocks out the first home run of his Major League Baseball career. Twenty years later, Aaron becomes baseball’s new home run king when he broke Babe Ruth’s long-standing record of 714 career homers. A native of Mobile, Alabama, Aaron began his professional baseball career in 1952 in the Negro […]

2:20m read

1961

Judy Garland plays Carnegie Hall

On April 23, 1961, Judy Garland performs a gig at Carnegie Hall, often referred to as “the greatest night in showbiz history.” She was one of the biggest and most popular movie stars of all time, making her first film appearance at the age of seven and earning the first of three Oscar nominations at […]

1:54m read

1969

Sirhan Sirhan receives death penalty for assassination of Robert F. Kennedy

On April 23, 1969, Sirhan Sirhan is sentenced to the death penalty after being convicted in the assassination of politician Robert F. Kennedy. In 1972, Sirhan’s sentence was commuted to life in prison after California abolished the death penalty. In the early morning hours of June 5, 1968, Robert Kennedy, a U.S. senator from New […]

2:08m read

1975

President Ford says that war is finished for America

At a speech at Tulane University, President Gerald Ford says the Vietnam War is finished as far as America is concerned. “Today, Americans can regain the sense of pride that existed before Vietnam. But it cannot be achieved by re-fighting a war.” This was devastating news to the South Vietnamese, who were desperately pleading for […]

2:16m read

1985

New Coke debuts, one of the biggest product flops in history

On April 23, 1985, The Coca-Cola Company announces that it is changing the formula of its signature soft drink for the first time in 99 years. The short-lived, sweeter New Coke, as it is called, debuts to a consumer backlash that pundits call the marketing blunder of the century. Coca-Cola, which had been the world’s […]

1:28m read

European History

43 videos

European History

The Witch Hunter Who Helped Shape America’s Witch Trials

Matthew Hopkins terrorized 17th-century England and left a legacy that would reach Salem decades later.

European History

What Inspired Queen ‘Bloody’ Mary’s Gruesome Nickname?

She did burn hundreds of Protestants at the stake, but also history, as they say, is written by the victors.

European History

How the 1966 Aberfan Mine Disaster Became Elizabeth II’s Biggest Regret

The Aberfan disaster wiped out a generation of Welsh schoolchildren and devastated the nation.

About the author

HISTORY.com Editors

HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion, Christian Zapata, Cristiana Lombardo and Adrienne Donica.

Fact Check

We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate.