several versions of the saga allege that alan had boasted that it was no harder to sail to norway than it was to sail from norway to scotland, suggesting that alan thought himself capable of even invading norway. in fact, this bluster may well have been designed by amlaíb dub to direct further norse animosity at alan. whatever the case, the saga reveals that hákon had begun preparations for a military campaign in the isles well before amlaíb dub's arrival. in fact, the king is stated to have appointed a certain óspakr as king of the isles, giving him command of the norwegian fleet tasked with restoring peace in the region. within days of amlaíb dub's arrival in norway, óspakr's twelve-ship fleet set sail for the isles, gaining another twenty after reaching orkney. the campaign itself is documented in several sources, such as the "chronicle of mann", the "chronicle of lanercost", and the icelandic annals, with the most detailed source being "hákonar saga hákonarsonar". once in the isles at islay, the fleet met up with three members of the meic somairle, apparently kinsmen of óspakr, including the aforementioned sons of dubgall mac somairle. at about this point, the saga states that the fleet had reached a size of eighty ships, a number which suggests a fighting force of about three thousand men.