One of the most important colonial institutions which joined church and society in the Brazilian cities were the lay confraternities which were attached to churches, convents and monasteries. These voluntary associations of laymen and women joined people of all classes and races in common religious activities and social works of mercy. In colonial Brazil there were separate lay associations for different races, although these racially suggested societies might parade together during religious festivals and share side altars in a common church. Free blacks, mulattoes and slaves joined separate religious associations since the white confraternities were very exclusive and discriminatory towards the poorer non-white population. The slave confraternities of the cities of 18th century Brazil were the only lay religious associations in that society which were open to all people regardless of class, race, sex or ethnic background. However as the century wore on some of the black brotherhoods tended to differentiate among themselves according to tribal distinctions, language, social condition and the extent of assimilation in Portuguese America. The larger slave confraternities like the Rosary brotherhood usually had a more diverse membership of free and slave brothers, mulattoes, Creoles and tribal Africans, blacks and whites.