Amlaíb (Óláfr) Cuarán (d. 981), son of Sitriuc Cáech (qv), was Norse king of Dublin. He first came to notice in 940 when he left Dublin to join his cousin Amlaíb (qv) son of Gofraid at York. In 941, when Amlaíb son of Gofraid died, Amlaíb Cuarán himself became king of the Hiberno–Danish kingdom of York and Dublin, but he lost control of Danish Mercia to King Edmund of Wessex the following year. A year later, however, he made peace with Edmund and was baptised at his court, Edmund acting as sponsor. Amlaíb's cousin, Ragnall son of Gofraid, was later confirmed there in the same manner. This did not really change matters, as Edmund invaded Northumbria in 944, driving out Amlaíb and Ragnall. According to William of Malmesbury, Amlaíb then renounced his baptism (an act that outraged Edmund) and returned to Dublin. In late 948 or early 949 he returned to York to begin his second reign, which lasted till 952, when he was expelled by the Norwegian leader Eirikr Bloodaxe.
Amlaíb Cuarán's Irish career is also of great importance. On returning from England in 945, he formed an alliance with the able king of Brega, Congalach Cnogba (qv) of the Sil nÁedo Sláine, who was making a bid for the high-kingship, from which his dynasty had been excluded for over two centuries. Amlaíb was forced to depose his cousin Blacair (qv), a junior kinsman who had been left in control of Dublin and had proclaimed himself king of the city in Amlaíb's absence. Blacair decided to abdicate, but in 948 he was defeated and slain by Congalach; according to the annals, 1,600 of Blacair's men were either killed or captured. That same year, the vikings of Dublin assisted Congalach in defeating and killing his rival from the Cenél Conaill dynasty, Ruaidrí Ua Canannáin (qv). Although he was slain, Ruaidrí is said to have been victorious in the battle. Amlaíb then left his brother Gofraid to rule Dublin on his behalf. Gofraid wasted little time: the bell-house of Slane was burned by the Dublin Norse in 950, while the following year the churches of Meath were plundered from a base at Kells. The annals record a ‘great outbreak of leprosy among the foreigners of Dublin’ that year.
On Amlaíb's return to Dublin in 952, relations between him and Congalach began to deteriorate, the friction between the former allies being mostly due to Congalach's interference in Dublin's sphere of influence in north Leinster. In 956, Amlaíb received intelligence of Congalach's whereabouts on the way from Leinster, and was able to surprise him at a place called ‘Tigh-Gighrainn’, where Congalach and many of his nobles were captured and slain. In 962, the monastery of Kildare was plundered by the vikings of Dublin, while the following year Amlaíb's son Gofraid died. In 967, Kells was plundered by Amlaíb's sons. The following year, Amlaíb launched another attack on Kells, defeating the Uí Néill in a battle at Ard Máelchon (Ardmulchan parish, barony of Skreen, Co. Meath). Around this time he is referred to as ‘lord of the foreigners’.
From this point on, Amlaíb had to deal with a series of very able Irish kings, who seriously curbed his power. In 969 the high-king Domnall Ua Néill (qv) attacked the ‘foreigners’; a decade later, in 979, the king of Mide, the famous Máel-Sechnaill (qv) son of Domnall, defeated the forces of Amlaíb's sons at the battle of Tara, in which Amlaíb's son Ragnall was killed. In 980, Máel-Sechnaill, now high-king, led a great army against Dublin, capturing the city after a siege of three days and three nights. Máel-Sechnaill not only released thousands of Irish hostages and slaves but also took many jewels and other plunder, also freeing Mide from any ‘tribute or exaction’. The Annals of Ulster state that Amlaíb had viking allies from the Hebrides and Man, and that ‘very great slaughter was inflicted on the foreigners therein, and foreign power [ejected] from Ireland’. Amlaíb abdicated that same year and went on pilgrimage to Iona, where he died in 981 ‘after penance and a good life’.
Amlaíb Cuarán is important for his long reign and involvement with the Scadinavian kingdom of York, and for his being the last Dublin king to rule from York, as well as becoming a Christian king of Dublin. It has been said, however, that his military and political career was ‘too erratic to produce any lasting results’. The Cuarán element of his name, signifying sandal-making, is thought to refer to his inauguration as king of Dublin with a ceremonial sandal, in imitation of some Irish dynasties, or perhaps it was used as a form of insult. His court at Dublin made a lasting impact on Scandinavian folklore; he appears as the protector of Óláfr Tryggvason of Norway and as ‘Havelock the Dane’ in Anglo-Danish tradition. Amlaíb was succeeded by his son Glúniarainn, who reigned 980–89. Another of his sons, Sitriuc Silkbeard (qv), enemy of Máel-Sechnaill and Brian Bórama (qv), also reigned as king of Dublin from 989 to 1036, when he was deposed. Amlaíb's other sons include Aralt, Dubgall, Gofraid, and Ragnall.