Protestantism is one of thirteen eligible religions featured in the Gods & Kings and Brave New World expansions for Civilization V. It is an offshoot of Christianity that is introduced along with Catholicism and Eastern Orthodoxy in Brave New World.
Unlike the religions in Civilization IV, this religion has no technological requirements to be unlocked and neither unique buildings nor a unique missionary unit. Like all other religions, Protestantism can be founded directly after using a Great Prophet's Found Religion ability and only one civilization can be the founder of this religion.
The Protestant Reformation, as a movement that would eventually divide Christian Europe, began as a protest in Germany against Catholic doctrine and practices, especially in regard to salvation, justification and interpretation of the Bible.
Based upon his readings of humanist scholars, in 1517 AD Martin Luther, a German priest in the university town of Wittenberg, published his 95 theses criticizing certain practices of the Catholic Church. His example saw other liberal religious thinkers advance their own critiques of the church, and "evangelical" Lutheran denominations sprang up across Germany and Scandinavia, "reformed" creeds in Switzerland under John Calvin. Meanwhile, religion became mixed with politics in England and elsewhere, bringing yet more Protestant churches into existence. Although with some differences, all the Protestant movements maintained two tenets: that the Bible, rather than papal interpretation, was the sole source of authority for Christians; and that salvation comes only through a personal connection with Jesus as the Christ rather than through good works or indulgences.
The split in the Catholic faith would ignite a series of religious wars, echoes of which resonate still. Despite numerous movements and divisions with Protestantism since, its many denominations together number about 670 million members.