The president of the Council owed his position to both his party's majority in the Legislature (and to his party's willingness to support him in the Chamber) and to the Emperor, and these two sources of authority (parliamentary backing and imperial appointment) could sometimes come into conflict.
The shortest prime-ministership was the first of the three periods of Zacarias Góis e Vasconcellos in office, when he occupied the presidency of the Council for just a few days in May 1862 before being replaced.