Early in the year 1057, a preacher named
Ariald arrived in the city of Milan and began to preach against the Milanese clerics' custom of marrying. It is possible that he took advantage of the absence at this time of the Archbishop of Milan,
Guido da Velate, who was in Germany in August at the Council of Tribur. The Milanese clergy grew concerned by Ariald's attempt to whip up the city against them, and sent envoys to
Pope Stephen IX in Rome. On hearing this, Ariald travelled to Rome himself. Pope Stephen IX was sympathetic to Ariald's position, and sent two envoys to Milan,
Hildebrand of Sovana (later Pope Gregory VII) and
Anselm of Baggio (later Pope Alexander II). Ariald also returned to Milan, and now began to criticise the Milanese clerics' practice of simony, resulting in urban unrest. Ariald's close associate Landulf Cotta was attacked, and later died from his injuries. In 1059 Ariald travelled to Rome again to seek advice; Pope Stephen IX again sent envoys to Milan, this time
Peter Damian and again Anselm of Baggio, but this did nothing to quell the unrest in the city. In 1063, Landulf Cotta's brother
Erlembald went to Rome where he obtained a papal banner from the newly elected
Pope Alexander II in support of the Pataria movement. In 1066, Pope Alexander II finally excommunicated Archbishop Guido. Guido used this excommunication, however, to whip up the citizens' anger against the Patarenes at a public meeting, and Ariald was first chased out of the city of Milan, and then assassinated, in June 1066. However, when Ariald's body was found in May 1067, it quickly became the object of a cult, and popular opinion in Milan swung back behind the Pataria. Archbishop Guido was forced out of the city, leaving it under the control of Erlembald, and Alexander II formally proclaimed Ariald to be a saint in 1068. Archbishop Guido resigned in 1068, in favour of his associate
Gotofredo da Castiglione, who was also supported by
Emperor Henry IV. The papacy and the Pataria however supported a different candidate as archbishop,
Attone, and
Pope Gregory VII excommunicated Gotofredo in 1074. Rioting in Milan led to the murder of Erlembald in 1075, and after this point, the Pataria movement lost much of its energy. The controversy over the appointment of the archbishop of Milan continued, however, and contributed to the political tensions between Emperor Henry IV and Pope Gregory VII. == Medieval historiography ==