 As the numbers declined, cotton mills opened in the surrounding towns, Bury, Oldham (at its zenith the most productive cotton spinning town in the world), Rochdale, Bolton (known as ""Spindleton"" in 1892) and in Blackburn, Darwen, Rawtenstall, Todmorden and Burnley.As the manufacturing centre of Manchester shrank, the commercial centre, warehouses, banks and services for the 280 cotton towns and villages within a 12-mile radius of the Royal Exchange grew.The term "Cottonopolis" came into use in about 1870.