Glen check or glen plaid is derived from Glenurquhart in Scotland, where the New Zealand-born Countess of Seafield, Nina Caroline Ogilvie-Grant, had the design developed to use for her gamekeeper’s outfits in the early 19th Century. The pattern came to true popularity when Edward VIII, as Prince of Wales, visited the Seafield estate to hunt and took a fancy to the design, having some cloth created for himself in brown and cream - hence it’s other name, the Prince of Wales check.
While Prince of Wales checks have generally become smaller and finer over time, the term glen check today tends to refer to designs of a larger scale, in keeping with the original Scottish pattern.