It was proclaimed in 1891 and named after George Montagu, 6th Duke of Manchester who was the father-in-law of the Earl of Kintore GCMG, the Governor of South Australia at the time.

[1] The county was named by Algernon Keith-Falconer, 9th Earl of Kintore, the Governor of South Australia after his father-in-law, George Montagu, 6th Duke of Manchester.

It covers an area of 250 square kilometres (95 sq mi) and is named after John Castine, a member of the Parliament of South Australia.

It covers an area of 230 square kilometres (90 sq mi) and is named after William Copley, a former member of the South Australian Parliament.

[14][1] Its extent includes parts of the localities of Carriewerlow, Mount Arden, Lincoln Gap and Port Augusta West.

It covers an area of 400 square kilometres (154 sq mi) and is named after John Jenkins, a former member of the South Australian Parliament.