 Domnall 's rise to power in the Kingdom of Dublin took place in 1075 , after the expulsion of the reigning Gofraid mac Amlaíb meic Ragnaill , King of Dublin by the latter 's overlord , Toirdelbach Ua Briain , King of Munster . The circumstances surrounding Domnall 's accession are uncertain . He may have collaborated with Gofraid to <unk> the kingdom from the grip of the Uí Briain , or he may have been installed in the kingship by Toirdelbach himself , and ruled under the latter 's <unk> . Whatever the case , Domnall died within the year , and Toirdelbach placed his own son , <unk> , upon the throne . 
