Don Guillén was a highly educated man who had moved in the highest circles of political power in Spain. What prompted him in 1641 to begin formulating plans for rebellion and independence in New Spain is not clear, but the writings confiscated at the time of his arrest indicate that he was informed about political philosophy of popular sovereignty. When he was arrested 26 October 1642, there was a large cache of papers where he lived, which including a proclamation of independence, and other writings spelling out his political ideas and plans for rebellion. A key point in his political thinking was that the Spanish crown lacked legitimacy to rule New Spain, closely following the reasoning of the likes of sixteenth-century critic Bartolomé de Las Casas. He proposed for New Spain political sovereignty under the rule of a monarch with limited powers popularly chosen by groups who actively supported rebellion and independence.