The "constitution" of the Empire was still largely unsettled at the beginning of the 15th century. Although some procedures and institutions had been fixed, for example by the Golden Bull of 1356, the rules of how the king, the electors, and the other dukes should cooperate in the Empire much depended on the personality of the respective king. It therefore proved somewhat damaging that Sigismund of Luxemburg (king 1410, emperor 1433–37) and Frederick III of Habsburg (king 1440, emperor 1452–93) neglected the old core lands of the empire and mostly resided in their own lands. Without the presence of the king, the old institution of the Hoftag, the assembly of the realm's leading men, deteriorated. The Imperial Diet as a legislative organ of the Empire did not exist at that time. Even worse, dukes often went into feuds against each other that, more often than not, escalated into local wars. Map of the Empire showing division into Circles in 1512 Simultaneously, the Church was in a state of crisis too, with wide-reaching effects in the Empire. The conflict between several papal claimants (two anti-popes and the legitimate Pope) was only resolved at the Council of Constance (1414–18); after 1419, much energy was spent on fighting the Hussites. The medieval idea of unifying all Christendom into a single political entity, of which the Church and the Empire were the leading institutions, began to decline. With these drastic changes, much discussion emerged in the 15th century about the Empire itself. Rules from the past no longer adequately described the structure of the time, and a reinforcement of earlier Landfrieden was urgently called for. During this time, the concept of "reform" emerged, in the original sense of the Latin verb re-formare, to regain an earlier shape that had been lost. When Frederick III needed the dukes to finance war against Hungary in 1486 and at the same time had his son, later Maximilian I elected king, he was presented with the dukes' united demand to participate in an Imperial Court. For the first time, the assembly of the electors and other dukes was now called the Imperial Diet (German Reichstag) (to be joined by the Imperial Free Cities later). While Frederick refused, his more conciliatory son finally convened the Diet at Worms in 1495, after his father's death in 1493. Here, the king and the dukes agreed on four bills, commonly referred to as the Reichsreform (Imperial Reform): a set of legal acts to give the disintegrating Empire back some structure. Among others, this act produced the Imperial Circle Estates and the Reichskammergericht (Imperial Chamber Court); structures that would—to a degree—persist until the end of the Empire in 1806. However, it took a few more decades until the new regulation was universally accepted and the new court actually began to function; only in 1512 would the Imperial Circles be finalized. The King also made sure that his own court, the Reichshofrat, continued to function in parallel to the Reichskammergericht. In this year, the Empire also received its new title, the Heiliges Romisches Reich Deutscher Nation ("Holy Roman Empire of the German Nation").