The comuneros were the rebels who tried to overthrow the Royal Council and set up their own government. Their firmest base of support was the middle and upper-middle classes. The monied elite had been treated well under the regime of Ferdinand and Isabella, but had seen their standing decay under the Royal Council to the most powerful nobles. Some nobles (especially "low" nobles) threw their lot in as well, jealous of the foreigners who occupied many of the prestigious positions of government under Charles. The rural peasants generally had conflicted loyalties.
In the second phase of the rebellion, the revolt took a strongly antiseigneurial turn under Bishop Antonio de Acuña and others. This helped make the peasants friendlier to the comuneros' cause at the cost of repelling many powerful nobles worried about their privileges.