The rise of centralized kingdoms among the Sakalava, Merina and other ethnic groups produced the island's first standing armies, first equipped with spears, but later with muskets, cannons and other firearms. King Ralambo (1575–1612) raised the first standing army in the highland Kingdom of Imerina with a handful of guns, although for at least two centuries the armies of the Sakalava were much larger and better equipped, possessing thousands of muskets obtained principally through trade with European partners. By the early 19th century, however, the army of the Kingdom of Imerina was able to bring much of the island under Merina control. Merina Queen Ranavalona, like her predecessors, utilized the tradition of "fanampoana" (service due to the sovereign in lieu of taxes) to conscript a large portion of the population of Imerina into military service, enabling the queen to raise a standing army that was estimated at 20,000 to 30,000 soldiers.