Hidalgo y Costilla was born in the Corralejo Hacienda in Pénjamo, Guanajuato,[1] to a criollo family (historically, a Mexican of unmixed Spanish ancestry). Growing up in an hacienda, where his father Cristóbal Hidalgo y Costilla was employed as a superintendent, Hidalgo y Costilla developed an early sympathy for the unskilled Amerindian workers. He trained as a priest, retained an interest in political and social questions, which he carried with him to his first parish in the town of Dolores, now called Dolores Hidalgo, in the modern-day central state of Guanajuato. He learned several indigenous Amerindian languages, wrote texts in the Nahuatl (Aztec) language and organized the local communities in Michoacán.
In 1808, Spain was invaded by French troops, and Napoleon forced the abdication of King Ferdinand VII of Spain in favour of the French emperor's brother Joseph Bonaparte, prompting the Spanish colonial government to oppose the new king. Many Mexicans became divided and formed secret organizations; some supporting King Ferdinand VII, and others desiring independence from Spain. It is impossible to say exactly when Hidalgo turned his thoughts towards rebellion against the colonial power, but the break is thought to have come sometime after Bonaparte replaced Ferdinand on the throne of Spain.
Organizations began to emerge, expressing a variety of radical views, discontented against the French political leadership; and issues of Spanish oppression in the Spanish Empire. Hidalgo y Costilla, a priest of unconventional views, attended one such provincial group in Guanajuato. It was there that educated criollos started conspiring for a large-scale uprising of mestizos and indigenous Amerindian peasants.
http://en.wikipedia.org/wiki/Miguel_Hidalgo