Sir William Maclellan, created 1st Lord Kirkcudbright, was the son of Sir Patrick Maclellan of Bombie, and is best remembered for an undertaking inspired by a proclamation of King James II of Scotland that promised the barony of Kirkcudbright to whoever should disperse a troublesome thief known as Black Morrow 'dead or alive'.
This act was duly accomplished in some style by the young Maclellan, who presented himself before the king with the head Black Morrow on the point of his sword.
The king, surprised that the robber had been ousted, commended Maclellan on his service to the Crown but mentioned nothing of the Barony. Apparently, the enraged Maclellan threw his gauntlet at the king having it land at his feet and shaking his fist beseeched the king to "Think on!" (or remember what was promised), whereupon King James relented and awarded Maclellan the Barony and Castle.
The crest which the new Lord Kirkcudbright adopted was 'an erect right arm grasping a dagger, on the point of which was Black Morrow's head (later representations show a blackamoor's head) 'couped proper', tag on the bottom with the family motto "think on". The Coat of arms on the crest is flanked on either side by Maclellan on the right holding the Barony in his bare right hand and Maclellan's horse in full armourment.