William Irvine, or William de Irwyn, 1st Laird Drum, born about 1298, had a crown grant of the lands and forest of Drum in 1323. Served as Clerk of the Rolls for Scotland from 1328-31.

During his famous campaign against the English, Robert the Bruce often sought help and refuge from his kinsmen, the Irvines of Bonshaw. He chose William de Irwyn as one of his principle aides and companions. As the story goes, at one point King Robert found himself put to flight by his enemies with only a few of his aides around him. Exhausted by the chase, the King was compelled to sleep under a holly tree while William stood guard over him. Holly leaves are now a prominent feature in all seven family crests which represent the major branches of the Irvine clan. William stood by King Robert again at the famous battle of Bannockburn in June of 1314 (one of the few battles where the Scots defeated the English) and for his service was awarded the Royal Forest of Oaks in Aberdeenshire and Drum Castle which guards it in 1323. From that point on Drum Castle was continually occupied by the Irvines for over 650 years. This land had previously belonged to John Comyn. Drum was made into a free barony in 1329. Sir William de Irvine married a granddaughter of Bruce, who was the daughter of Robert Douglas, Earl of Buchan. From this union was derived the two great families of Bonshaw and Drum.  For thirteen generations, starting with the second Laird of Drum, there was a successive line of Irvines all bearing the name Alexander.