John Knox (c. 1514 - 1572) was the founder of the Church of Scotland and one of the leading figures of the Scottish Reformation. Born and raised in Scotland, he was educated at St. Andrews and, in 1536, was ordained as a priest. After working as a notary and private tutor, he became a follower of George Wishart, a Protestant reformer who was subsequently burned at the stake for heresy.
Knox joined Wishart's supporters in the occupied castle of St. Andrews, serving as their minister. It was here that he began his preaching career. Upon the surrender of the castle, he was held as a galley prisoner by the French for a year and a half.
After his release, he was for several years part of the radical wing of the Church in England, but he went into exile on the continent upon the accession of Mary to the throne. He spent 6 years on the continent, in Geneva and elsewhere, preaching to the English exiles, and only returned to in 1559 after the accession of Elizabeth I in England. Travelling to Scotland where he arrived in the midst of widespread tension and turmoil, he preached a sermon on 11 May 1559 against idolatry (directed at the Catholic mass, which was held by the reformers to be a type of idolatry). This sermon sparked widespread rioting and is usually hailed as the start of the Scottish Reformation. Although Knox was the chief polemicist on behalf of the victorious Protestants in the civil strife that followed, the subsequent course of events in the Scottish Reformation was insufficiently radical for his tastes.
Knox's principal literary work is his History of the Reformation, still considered a valuable source on the religious events of those times.