Tartan on the Bias?

[jhockin]

The earliest bias cut tartan jacket I'm aware of is that worn by Col Alasdair Macdonnell of Glengarry in Raeburn's 1812 portrait. Glengarry was a bit of a dandy and perhaps started the fashion. Any style of tartan coat generally disappeared during William IV's reign in favour of plain coats although the odd one was still being worn later, probably older ones rather than contemporary with the date of the picture/portrait in which they appear.

Can't recall the date, but if you check the painting of the battle of Culloden, where Highlands are in close quaters with English soliders, you'll note some of the Highlanders wearing jackets and vest, cut on the bias - pretty sure these were painted earlier than 1812 ...