The word paladin was first used in Ancient Rome for a chamberlain of the Emperor, and also for the imperial palace guard, called the Scholae Palatinae by Constantine. In the early Middle Ages, the meaning changed and the word was used for one of the highest officials of the Catholic Church in the pope's service and also for one of the big nobles of the Holy Roman Empire, who was then named Count Palatine. The word paladin was also used in 19th century Hungary and in the German Empire and United Kingdom during the early 20th century.