GREGORY IV.

gregory iv., pope from 827 to 844, was chosen to succeed valentinus in december 827, on which occasion he recognized the supremacy of the frankish emperor in the most unequivocal manner. his name is chiefly associated with the quarrels between lothair and louis the pious, in which he espoused the cause of the former, for whom, in the campus mendacii (_lugenfeld_, field of lies), as it is usually called (833), he secured by his treachery a temporary advantage. the institution of the feast of all saints is usually attributed to this pope. he died on the 25th of january 844, and was succeeded by sergius ii. gregory v. (bruno), pope from 996 to 999, a great-grandson of the emperor otto the great, succeeded john xv. when only twenty-four years of age, and until the council of pavia (997) had a rival in the person of the anti-pope john xvi., whom the people of rome, in revolt against the will of the youthful emperor otto iii., had chosen after having expelled gregory. the most memorable acts of his pontificate were those arising out of the contumacy of the french king, robert, who was ultimately brought to submission by the rigorous infliction of a sentence of excommunication. gregory died suddenly, and not without suspicion of foul play, on the 18th of february 999. his successor was silvester ii.