The original seat of the Earls of Carnwath was at Dalzell House, Motherwell, North Lanarkshire. This formed part of the larger Carnwath Estate including the barony of Dalzell, which had been held by the family since the fourteenth century. This was to be sold by the third and fourth Earls to help pay the fines of their father and grandfather for their part in supporting the Royalist side during the English Civil War. It was to be bought by Sir George Lockart, and the Hamilton family, later Barons Hamilton of Dalzell.