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- September 21, 1170
MacMurrough and the Normans March on the Norse Kingdom of Dublin

In 1170, Diarmait Mac Murchada, the deposed King of Leinster, led an expedition to retake power in Ireland with the help of Norman mercenaries, notably Richard de Clare, better known as Strongbow. After their success at Wexford and Waterford, MacMurrough and the Normans marched on Dublin, a key Norse-Gaelic stronghold and a strategic target.
An Irish force under Roderic O’Connor, the High King of Ireland, had positioned itself south of Dublin to intercept them. However, MacMurrough and his allies circumvented this threat, taking a northern route and attacking Dublin from an unexpected direction.
The city’s defenders were caught off guard, and Dublin fell swiftly to the invading force. Askulf Ragnaldson, the King of Dublin, and many Norse inhabitants fled by sea, seeking refuge in the Hebrides or the Isle of Man, both Norse-dominated regions at the time.
This capture marked a turning point in Irish history, as it solidified the Norman foothold in Ireland and undermined the Norse presence that had lasted for centuries. It also set the stage for deeper Norman intervention and eventual English rule over much of Ireland.