The term 'Welsh' appeared in the earlier English form of Weallise and the mediaeval form Wallensis, and was applied to the British peoples from Strathclyde in Scotland to Brittany in France who spoke that branch of the Celtic family of languages now represented by Breton and Welsh. In the 12th century the Kings of Scots were still addressing their subjects as distinct ethnic groups: French and English, Scots and Welsh. Hence the surnames Inglis, Scott and Wallace. The ancient captial of Strathclyde is still remembered as Dumbarton, the Fortress of the Britons. 

In the second half of the 12th century a man called Richard, defined as a Wallace, obtained lands in Ayrshire, which belongs to the former Kingdom of Strathclyde. His property was called Richardston, now Riccarton; and his great-grandson, Sir Malcolm Wallace, received the lands of Elderslie in Renfrewshire. Such was the background of Malcolm's son William, who was to evoke a national spirit which united so many disparate peoples and to earn his place as Scotland's greatest patriot.

The Clan Wallace did not descend from Sir William Wallace but from the Riccarton Branch. The current chief of the clan, Ian Wallace, is recognized by the Lord Lyon King of Arms as the head of all branches, Renfrewshire, Riccarton, and Craigie.