General Notes

William Douglas, 1st of Douglas; born 1174; died 1213.  [Burke's Peerage]

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Copied from "Douglas Family" by Mark Freeman, freepages.genalogy.rootsweb.com/~markfreeman/douglas.html:
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Notes for William de Duglas:
The first recorded use of the Douglas surname was by William de Duglas, who signed numerous official charters between 1175 and 1213. William, who died in 1214, was the father to six sons and a daughter. Along with Archibald de Douglas, heir to the Douglas estates, there were Brice (Bishop of Moray), Alexander (Canon of Spynie and Vicar of Elgin), Henry (Canon of Spynie and Clerk of Bishop), Hugh (Archdeacon of Moray), Freskin (Dean of Moray), and Margaret.

http://amg1.net/flemfam.htm
Although William de Douglas was the first known owner of Douglasdale, holding that land between 1174 and 1213, there is no reason to doubt that his father was Theobaldo Flamatico or Theobald the Fleming. The family's arms indicate the kinship with Murray and a descent like that of Brodie and Innes, from a third son of the house of Boulogne. In Flanders there was a family of the Theobalds who were hereditary castellans of Ypres between about 1060 and 1127, after which their history becomes obscure. Theobald's lands in Scotland were granted to him soon after 1150 by the Abbot of Kelso. William de Douglas, the heir, having married the sister of Friskin de Kerdale or Freskin of Moray, had by her six sons; the five younger of them all went to Moray to support their uncle there and his own heir, Archenbald, stayed in Lanarkshire to inherit the Douglas estates. He married a daughter of Sir John Crawford.