Why did Henry VIII change his religion?

Until the 16th century, England was officially Roman Catholic and considered the Pope to be their religious leader. When Henry VIII, who lived from 1491 to 1547, decided he wanted to divorce his wife Catherine of Aragon, he had to ask for permission from the Pope. The Roman Catholic Church holds that marriage is for life, and only in exceptional circumstances may an annulment be granted. Because Henry wanted a divorce because Catherine was not giving birth to boys, the Pope turned down Henry's request. In 1534, Henry decided he was now the religious leader of England. With the Act of Supremacy, he established the Protestant Church of England. Though this formation was really motivated by his desire for a divorce, Henry was likely also inspired by the Protestant Reformation sweeping across mainland Europe. 
In 1517, Martin Luther produced his Ninety-Five Theses, a criticism of the decadence and wrongdoings of the Roman Catholic Church. This inspired the Reformation throughout Europe, and Henry's Act of Supremacy officially brought the Protestant Reformation to England. From that point on, the culture of religion and Christianity in England was forever changed. Religious power no longer lay with some absent power; instead, it was vested in the hands of the ruling monarch.