 Their domains, initially only the immediate surroundings of the castle included, increased steadily, mainly through acquisitions such as those from impoverished homes of Tübingen.At the Diet of Worms in 1495, Count Eberhard V was raised to Duke ("Herzog") by the German King, later Holy Roman Emperor, Maximilian I.During 1534 to 1537 Duke Ulrich introduced the Protestant Reformation, and the country became Protestant.