Indigenous cultures flourished in Ecuador long before the Inca Empire conquered the area in the 15th century. In 1534, the Spanish arrived and defeated the Incas. The indigenous people were decimated by disease in the first decades of Spanish rule. They also became forced laborers for the Spanish elite. In 1563, Quito became the seat of a royal audiencia (administrative district) of Spain. After independence-seeking forces defeated the royalist army in 1822, Ecuador joined Simón Bolívar's Republic of Gran Colombia, only to become a separate republic in 1830. The 19th century was marked by instability and a rapid succession of rulers.