Imperial Armada was a subtheme of Pirates that was introduced in 1996 and only had 3 sets that lasted one year. The Armada replaced the Imperial Guards as adversaries of the pirates. Imperial Armada minifigures were based on the Spanish conquistadors and the Spanish Navy of the 16th and 17th century.
Pirates was a LEGO theme introduced in 1989, running until 1997 and focused on the classic idea of Caribbean pirates that were pitted against soldiers of colonial empires. As the series progressed through the years, more factions were introduced and the older ones were phased out of production. The Pirates were one of the first two original factions in the theme to be introduced.