From the mid-1930s, the Greater London area comprised four types of local government authorities. There were county boroughs, municipal boroughs, urban districts and metropolitan boroughs. The large county boroughs provided all local government services and held the powers usually invested in county councils. The municipal borough and urban district authorities had fewer powers. The situation was made more complex because county councils could delegate functions such as elementary education and library provision to the municipal borough and district councils, and this was implemented piecemeal. Reform of London local government sought to regularise this arrangement.