 According to Njál 's saga , Gormflaith " egged on her son Sigtrygg very much to kill King Brian " , sending him to win the support of Earl Sigurd of Orkney , and Bróðir and Óspak of Man at any price . Sigtrygg arrived in Orkney for Sigurd 's Yule feast , where he sat in a high seat between the two brothers @-@ in @-@ law , Earl Sigurd of Orkney and Earl Gilli of the Southern Isles . The saga also records that Sigtrygg was very interested in the Burning of Njáll Þorgeirsson at Bergþórshvoll and what had happened since . Afterwards , Sigtrygg bade Sigurd to go to war with him against Brian . Despite Sigurd 's initial hesitance and against the advice of his men , he eventually agreed to arrive in Dublin by Palm Sunday with all his men , on the condition that if Brian was slain , Sigurd would marry Gormflaith and become King of Ireland . 
