The power dynamics of São Tomé in the 16th century were surprisingly diverse with the participation of free mulattos and black citizens in governance. Voluntary colonists shunned São Tomé for its disease and food shortages, so the Portuguese crown deported convicts to the island and encouraged interracial relationships to secure the colony. Slavery was also not permanent, as demonstrated through the 1515 royal decree granting the manumission of African wives of white settlers and their mixed-race children. In 1517,  another decree freed the male slaves who had originally arrived on the island with the first colonists. After 1520, a royal charter allowed for property-owning, married, free mulattos to hold public offices. This was followed by a decree in 1546 establishing civil equality between these qualified mulattos and the white settlers, allowing free mulattos and black citizens opportunities for upward mobility and participation in local politics and business. Social divisions led to frequent disputes within the colony's town councils and with the governor and bishop, with constant political unstability.