Child(ren):
The true progenitor of Clan Douglas was probably "Theobaldus Flammatius" (Theobald the Fleming), who received in 1147 the lands near Douglas Water in Lanarkshire in return for services for the Abbot of Kelso. The first certain record of the name Douglas is that of William de Dufglas who witnessed a charter between 1175 and 1199 by the Bishop of Glasgow to the monks of Kelso. In 1179 William Douglas was Lord of Douglas and it seems likely that he was Theobald the Fleming's son and the first to take the surname Douglas. His grandson, also Sir William de Douglas had two sons who fought at the Battle of Largs in 1263 against the Norsemen.
https://en.wikipedia.org/wiki/Clan_Douglas
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