A metropolitan borough (or metropolitan district) is a type of local government district in England. Created in 1974 by the Local Government Act 1972, metropolitan boroughs are defined in English law as metropolitan districts within metropolitan counties. All of the metropolitan districts have been granted or regranted royal charters giving them borough status (and in some cases, they also have city status). Metropolitan boroughs have been effectively unitary authority areas since the abolition of metropolitan county councils by the Local Government Act 1985. Metropolitan boroughs pool much of their authority in joint boards and other arrangements that cover whole metropolitan counties, such as city regions or combined authorities, with most of the latter having a metro mayor.