The "Chronicle of Melrose" reports that Somairle's forces were drawn "from Ireland and various places". Irish sources—such as the "Annals of Tigernach", "Annals of Ulster", and "Mac Carthaigh's Book"—specify that his forces consisted of men from Argyll, Kintyre, the Isles, and Dublin. Such depictions of Somairle's forces appear to reflect the remarkable reach of power that he possessed at his peak. The invasion was clearly a well-planned affair. According to the "Chronicle of Mann", Somairle's invasion fleet numbered one hundred and sixty ships. If each ship carried forty to fifty combatants, Somairle may have led between six thousand and eight thousand men. Although the tallies of combatants given by mediaeval sources are generally suspect, they can be indicative of the magnitude of a force's size. The participation of Dubliners in Somairle's venture suggests that he had an alliance with the Dubliners. Specifically, he may have had a pact with either the overlord of Dublin, Diarmait Mac Murchada, King of Leinster, or else with Diarmait's own overlord, Muirchertach Mac Lochlainn, High King of Ireland.