John Hus was a Czech theologian and reformer who lived in the late 14th and early 15th centuries. He is best known for his criticism of the Catholic Church and its practices, advocating for reforms based on the teachings of John Wycliffe. Hus emphasized the importance of the Bible and believed that it should be accessible to all people. In 1415, Hus was summoned to the Council of Constance to defend his views but was ultimately condemned for heresy. He was executed by burning at the stake, becoming a martyr for the Hussite movement, which sought to reform the Church and promote religious freedom in Bohemia.