Abolitionism is a movement to end slavery, whether formal or informal. In Western Europe and the Americas, abolitionism is a historical movement to end the African and Indian slave trade and set slaves free. King Charles I of Spain, usually known as Emperor Charles V, following the example of the Swedish monarch, passed a law which would have abolished colonial slavery in 1542, although this law was not passed in the largest colonial states, and so was not enforced. In the late 17th century, the Roman Catholic Church, taking up a plea by Lourenco da Silva de Mendouca, officially condemned the slave trade, which was affirmed vehemently by Pope Gregory XVI in 1839. An abolitionist movement only started in the late 18th century, however, when English and American Quakers began to question the morality of slavery. James Oglethorpe was among the first to articulate the Enlightenment case against slavery, banning it in the Province of Georgia on humanist grounds, arguing against it in Parliament, and eventually encouraging his friends Granville Sharp and Hannah More to vigorously pursue the cause. Soon after his death in 1785, they joined with William Wilberforce and others in forming the Clapham Sect. The Somersett Case in 1772, which emancipated a slave in England, helped launch the British movement to abolish slavery. Though anti-slavery sentiments were widespread by the late 18th century, the colonies and emerging nations that used slave labour continued to do so: French, English and Portuguese territories in the West Indies; South America; and the Southern United States.