Dispute over the Archbishopric of Milan

Timeline

1. c. 1060–1063Milan · LombardyMilanese citizens and clergy formed the Patarene movement, publicly denouncing Archbishop Guido for simony and accepting lay investiture, demanding the restoration of the Church's purity, echoing the reformers in Rome.
2. c. 1064–1067Milan · LombardyPope Alexander II supported the reformers and repeatedly condemned Guido; Emperor Henry IV upheld Guido's position and applied political pressure. Milan became the focus of struggle between papal and imperial power, both sides seeking to control the appointment of the archbishop.
3. c. 1067–1069Milan · LombardyStreet clashes and church occupations broke out between reformers and Guido's supporters, and Patarene leaders such as Ariald were persecuted. The struggle over the Archbishopric of Milan evolved from religious controversy into political violence involving citizens, foreshadowing the escalation of the broader Investiture Controversy.