Florian Geyer was born around 1490 at Geyer Castle in Giebelstadt, Lower Franconia. After the deaths of his father Dietrich (in 1492) and of his two older brothers, Florian Geyer inherited the family castle and fortune. In 1512 and 1513, he was a guest at the court of King Henry VIII in England, where he may have been exposed to the reformist ideas of John Wycliffe and the Lollards. In 1517, after refusing to pay 350-year-old interest claims from Neumünster Collegiate Church, Geyer was excommunicated.