Complex sentence: In November 1865, Colonel Mariano Ignacio Prado seized power from Pezet after a coup, and organized an effective defense against Spanish aggression that culminated with the Battle of Callao.
Split into simpler sentences: In November 1865, Colonel Mariano Ignacio Prado seized power from Pezet. Prado organized an effective defense against Spanish aggression that culminated with the Battle of Callao.