In a century and a quarter which witnessed three papal schisms and two bitter conflicts between pope and emperor, the papacy inevitably experienced prolonged periods of financial crisis. The first such period began in the last years of the pontificate of Gregory VII and continued into the early twelfth century. Until he was driven into exile in July 1084, Gregory's pontificate was comparatively sedentary by the standards of the central Middle Ages. The dating clauses of his letters and privileges show that for at least seven years and two months of his fifteen-year pontificate the papal government was stationed in the Lateran palace in Rome. For most of his pontificate, therefore, the pope had access to the revenues due to St Peter as landlord of the papal patrimony – the various rents, services and other dues claimed by all secular princes from their territories. But after the outbreak of hostilities between Gregory VII and Henry IV of Germany, these revenues were insufficient to pay for the defence of Rome against the emperor. The breakdown in the papal finances first became evident in May 1082, when the pope proposed to mortgage the property of the Roman church to pay for the war against the emperor. His proposal was vetoed by a meeting of the Roman clergy. Thereafter the sources reveal the pope's increasing dependence on the emergency supplies of his secular allies.