County Durham has long used the flag of Durham County Council as an unofficial flag of the county. This flag was the banner of arms of the County Council, based on the arms of the See of Durham (Azure a Cross Or between four Lions rampant Argent). In 1961 the council adopted a coat of arms based on those of the See, with the lions holding swords and wearing crowns and the addition of five black lozenges to represent the county's coal mining industries. After the Local Government Act 1972 came into effect County Durham lost territory in the north to Tyne and Wear and in the south to Cleveland, whilst gaining the Startforth Rural District from the North Riding of Yorkshire. The arms of the County Council were altered to their present form by replacing the central lozenge with a White Rose of York.