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. Although with some differences, all the Protestant movements maintained two tenets: that the “Good Book,” 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 a church-appointend intermediary.

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; soon “evangelical” Lutheran denominations sprang up across Germany and Scandinavia along with “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 Henry’s lust for Anne Boleyn had more to do with the English schism than belief).

The split in the Catholic faith would ignite a series of religious wars, Christians slaughtering Christians … echoes of which resonate still. Despite numerous movements and divisions within Protestantism since, its many, many (too numerous to keep track of) denominations together number about 670 million members.