"as if having imperial power in that place" The elected consuls, which Frederick had claimed the right to ratify, he began to designate directly. The business of the podestà was to enforce imperial rights. From the start, this was very unpopular, and their often arbitrary behaviour was a factor in bringing about the formation of the Lombard League and the uprising against Frederick in 1167. Although the Emperor's experiment was short-lived, the podestà soon became important and common in northern Italy, making their appearance in most communes around the year 1200, with an essential difference. These officials were now appointed by the citizens or by the citizens' representatives, rather like the older consuls (but not collegial). The podestà exercised the supreme power in the city, both in peace and war, and in foreign and domestic matters alike; but their term of office lasted only about a year. In order to avoid the intense strife so common in Italian civic life, it soon became the custom to hire a stranger to fill this position. Venetians were in special demand for this purpose during the 12th and 13th centuries. This was probably due to their lesser concern (at the time) than other Italians in the affairs of the mainland. Afterwards, in a few cases, the term of office was extended to cover a period of years, or even a lifetime. They were confined in a luxury palace to keep them from being influenced by any of the local families. The architectural arrangement of the Palazzo Pubblico at Siena, built starting in 1297, evokes the uneasy relation of the commune with the podestà, who in Siena's case was a disinterested nobleman at the head of the judiciary. It provided a self-contained lodging round its own interior court for the podestà, separate but housed within the Palazzo Pubblico where the councillors and their committee of nine habitually met. During the later part of the twelfth and the whole of the thirteenth century most Italian cities were governed by a podestà. Concerning Rome, with a history of civic violence, Gregorovius says that "in 1205 the Pope Innocent III changed the form of the civic government; the executive power lying henceforward in the hand of a single senator or podest, who, directly or indirectly, was appointed by the pope". In Florence after 1180, the chief authority was transferred from the consuls to the podest, and Milan