Discover the biography of Dom Pedro II! Dom Pedro II was the second and final Emperor of Brazil. He became regent prince at the age of five when his father Dom Pedro I abdicated the throne. At the age of 15, he was declared of age and crowned Emperor of Brazil. His reign, which lasted almost fifty years, began on July 23, 1840, and ended on November 15, 1889, when a Military Coup took place to establish the Republic.