descent but culturally European/Hispanic), next descendants of the natives who had collaborated with the Spanish conquest of Yucatán, and at the bottom were the other native indios and African slaves. Some historians have argued that the conflict was more of an inter-ethnic conflict than a caste conflict. It was the members of a large sector of the Maya, not fully assimilated or subdued and living for the most part in the east, who led the struggle. They rebelled against the whites, creoles, mestizos, and the assimilated Maya who lived in the area. Not all of the Maya participated in the revolt. For example, Maya in the southern region remained neutral for most of the conflict. In the northern portion of the peninsula, many Maya fought directly against the insurgents. The indigenous population was concentrated in the Campeche-Mérida region. This was known as the Camino Real, because the majority of the peninsulares and criollos lived in that area. The Maya roughly outnumbered the Latino and Spaniard groups by three to one throughout the Yucatán, but in the east, this ratio was closer to five to one. The elites maintained the strictest discipline and control over the Maya population in the east. The Catholic Church, generally allied with the stronger classes, also had a preponderant role where the military organization was strongest. During the Mexican War of Independence, the intelligentsia of Yucatán watched the events to the north. Following 1820 they organized their resistance to Spain, forming the Patriotic Confederation, which declared independence from Spain in 1821. The confederation subsequently joined the First Mexican Empire that same year; in 1823 it became a part of the federal Mexican government as the Federated Republic of Yucatán. The government of the republic, based in Mexico City, tended towards centralization, which some people in frontier areas resented. Near the end of the next decade, several provinces revolted against the central government, including Guatemala in the south and Texas in the north (which was receiving significant unsanctioned European immigration from the United States in the eastern section). To bear the costs of the war against Texas, the national government imposed several taxes, including raising importation duties and the movement of local goods. In response to this, on 2 May 1839, a federalist movement led by Santiago Imán created a rival government in Tizimín, which soon took over Valladolid, Espita, Izamal, and finally Mérida on the Yucatán