Said to be aged forty-six at the time of his father's death, this Patrick was the eldest son of Patrick I, Earl of Dunbar and Ada, daughter of King William of Scotland. He probably succeeded to his father's lands some time before the latter's death on December 31 1232, as his father was elderly and had been ill for some time.
He renounced his claim to some disputed Marches in lower Lauderdale to the monks of Melrose, and in 1235 he, with Adam, Abbot of Melrose, and Gilbert, Bishop of Galloway, led an expedition against an uprising in Galloway. He accompanied King Alexander II of Scotland to York and was a witness and guarantor to the treaty with King Henry II of England, in 1237.
Shortly after 1242 the Earl of Dunbar was sent to subdue the rebellious Thane of Argyll. The Earl held first rank among the twenty-four barons who guaranteed the Treaty of Peace with England in 1244.
Holinshed relates, he accompanied Lindsay of Glenesk, and Stewart of Dundonald to crusade, where he died in 1248 at the siege of Damietta in Egypt.
Before 1213, he married Euphemia (d. 1267 at Whittingehame), daughter of Walter FitzAlan, 3rd High Steward High Steward of Scotland and lord of Kyle, Strathgryfe and Bute.
Issue by Euphemia: