Where was shepherd's pie originally created?

Cooks Info asserts that shepherd's pie originated in Scotland and northern England. The dish came into existence after potatoes were accepted in the United Kingdom, which was at the end of the 1700s.

Before this point, a similar dish to shepherd's pie was commonly prepared in Scotland. Instead of potatoes, a pastry crust was used. The dish was not officially named until 1870. Shepherd's pie is commonly made with mutton or lamb. If the dish is made with another type of meat, it is referred to as cottage pie. Vegetables such as onion are used to season the meat. Peas are often included in shepherd's pie.