The Oxford Names Companion, OUP "Scottish Forenames" - Donald Whyte, FGH, FSG
Notes:
English, original form of Wilfred, from Old English/Old German "resolute for peace".
Wilfrid was common in the pre-Norman period in Britain. The use of the name died out until the 19th century since when Wilfred has become the preferred form.
Thanks to Donald Whyte who provided much of the initial information for this site.