It is apparent from Diaz's career since 1854 that he was, at heart, an intensely political animal, and a highly ambitious one. His immersion in radical (rojo or jacobino) liberal politics in Oaxaca, his tenure as military commander ofTehuantepec and, above all, his period as Commander of the Army of the East between 1863 and 1867 provided hirn with vital political experience and real political power, given that he was obliged to fulfil not just military, but administrative, judicial and legislative functions in the area under his command.