After President-elect Álvaro Obregón was assassinated on July 17, 1928, former president Plutarco Elías Calles began to be called el Jefe Máximo de la Revolución, “the Supreme Chief of the Revolution.” Others held the presidency. From 1928 to 1934, however, no political authority in Mexico was more important than Calles.
The period is known as the Maximato, after his title. President Lázaro Cárdenas ended it on the night of April 9, 1936.