[1] The prazo was a land grant/lease given in exchange for an annual fixed fee based on laws promulgated by Portuguese kings, such as Afonso V and Manuel I.
[3] The prazeiro was allowed to employ Africans (colonos); to raise a private army (often made up of slaves); trade in all commodities; and maintain law and order.
The Portuguese Crown intended the prazo to guarantee control over the land, stimulate agricultural production, facilitate European settlement, and be a source of revenue for the government, but the system failed in the objectives.
Contributions to the failure were rampant absenteeism, violent rivalries between the grantees, the scarcity of Portuguese women, lack of capital, and Africans, of which the latter cause was probably the most important.
Another attempt was made in the 1890s without result, but the introduction of the concessionaire companies about that time, the 1890 British Ultimatum and the Portuguese Colonial Act of 1930 contributed to the end of the prazo.