Monagas, José Tadeo (hōsāˈ täħāˈō mōnäˈgäs) [key], 1784–1868, Venezuelan political leader. He fought under Bolívar in the revolt against Spain. Chosen by José Antonio Páez as president in 1847, he set up a compromise administration. Páez subsequently revolted, but Monagas crushed the insurrection. In 1851, José Gregorio Monagas, a brother, was inaugurated, and in 1855 José Tadeo again took office. Reforms, including the emancipation of slaves, were introduced, but adoption of a new constitution led to a successful revolution (1858) against him. Ten years later he headed a counterrevolution with forces called the Azules [blues], but he died just after returning to power. His son, José Ruperto Monagas, continuing the dynasty, was overthrown by a new revolution that brought Guzmán Blanco to power.