 Their early investments included collieries at Gosforth, Heaton, New Benton, Tanfield, South Causey, North Biddick and Longbenton.His seat was Ravensworth Castle, Lamesley, Co. Durham and his London address from 1735 was 13, St James's Square.Liddell married Anne Delme (daughter of Sir Peter Delme) in 1735 and they had one daughter, Anne, who was a noted correspondent.