View Historical Events by Day: What Happened on April 23 in History?

The Viking invasion of England under the leadership of Ivar the Boneless results in the capture of Dumbarton.

The Norwegian King Olaf Tryggvason is defeated in the Battle of Svolder.

St. Brice's Day massacre in England: King Æthelred the Unready orders the killing of Danish settlers.

The Battle of Clontarf occurs near Dublin, Ireland, where the forces of Brian Boru, the High King of Ireland, defeat the Viking invaders. While Brian Boru's forces were victorious, the battle resulted in significant casualties, including Brian Boru himself. The battle is often seen as a pivotal moment in Irish history, marking a decline in Viking power in Ireland and contributing to the eventual unification of the country.

The Battle of Clontarf takes place at Clontarf, near Dublin, Ireland. between an army led by Brian Boru, High King of Ireland, against a Norse-Irish alliance comprising the forces of Sigtrygg Silkbeard, King of Dublin; Máel Mórda mac Murchada, King of Leinster; and a Viking army from abroad led by Sigurd of Orkney and Brodir of Mann. The battle It lasted from sunrise to sunset, and ended in a rout of the Viking and Leinster armies. More 

Edmund Ironside succeeds his father Æthelred the Unready as king of England.

Pope Nicholas II succeeds Pope Stephen IX as the 155th pope.

Thomas Becket, Archbishop of Canterbury, escapes from Northampton and flees to France.

Saladin becomes the emir of Egypt.

The trial and execution of Joan of Arc begin in Rouen, France.

Anne Boleyn, second wife of King Henry VIII, is arrested and imprisoned in the Tower of London.

William Shakespeare, English playwright, and poet is born in Stratford-upon-Avon.

The first King James Bible is published in London.

William Shakespeare dies in Stratford-upon-Avon on his birthday.

Soviet cosmonaut Vladimir Komarov is killed when the Soyuz 1spacecraft became entangled in its main parachute at an altitude of several miles and fell back to Earth.