Ímar (Ívaar) (d. 873), son of Gofraid, was joint king of the Scandinavians of Dublin. The Irish annals record that he came to Ireland around the mid ninth century and became joint ruler of viking Dublin with Amlaíb Find (Olaf the White). According to some accounts, Ímar, Amlaíb, and a third Scandinavian noble named Oisle were brothers, sons of Gofraid, a Norwegian king; the three certainly collaborated in various military activities.
Throughout the 850s and 860s the Dublin vikings were involved in ongoing warfare against the neighbouring Irish dynasties of Uí Dúnlainge of northern Leinster and Síl nÁedo Sláine of Brega; it is clear that Ímar was party to at least some of these ventures. He had assumed a prominent role by 858 at the latest, in which year he supported the king of Osraige, Cerball (qv) son of Dúngal, in a campaign against the Gall-Gáedil (a mixed band of Scandinavians and Irish) in Ara Tíre, a district in north-west Tipperary. The following year, Ímar and Amlaíb accompanied Cerball on an expedition into Meath. In 863 Ímar, Amlaíb, and Oisle made an incursion into the Boyne valley, and plundered several of the megalithic tombs including Knowth and Dowth. They also raided the territory of the king of Brega, Flann son of Conaing. Three years later, after an expedition to Scotland, Ímar and Amlaíb slew Oisle. In 870 Ímar again campaigned in Scotland with Amlaíb and they ravaged the kingdom of Strathclyde before returning to Dublin with many prisoners. The next year, Ímar plundered the midlands of Ireland with his nephew, Amlaíb's son.
In 873 Ímar died suddenly – of a painful disease, according to some Irish chroniclers. In his obit he is styled ‘king of the Northmen of all Ireland and Britain’. The years that followed saw the Irish Scandinavian ruling lineages racked by dissension, facilitating, apparently, the emergence of the Osraige king Cerball as ‘protector’ of Dublin. Nonetheless, an unnamed son of Ímar features prominently in the record: he burned Lismore in 883, and in 893 opposed a dynast named Sicfrith in an internal conflict that led to the demise of the first Dublin kingdom in 902.