Church canon law system

Timeline

1. 300–800Rome · RomeResolutions of ecumenical councils such as Nicaea, papal letters, and the writings of the Church Fathers constituted the early sources of canon law. Local synods and diocesan customs gradually accumulated, forming a dispersed tradition of legal compilations that laid the foundation for later systematic codification.
2. 1000–1130Roman Curia · Roman CuriaThe 11th-century church reform strengthened papal authority, and papal jurisdiction expanded in areas such as marriage, vows, and clerical cases. Papal courts and local episcopal courts operated in parallel, and disputes over the jurisdictional scope of canon law and secular law became a political focus.
3. 1135–1145Bologna · BolognaGratian compiled the Decretum Gratiani in Bologna, systematically organizing the sources of canon law through a method of reconciling contradictions, and it became the core textbook of canon law scholarship. Between 1131 and 1140, canon law education rose, providing the scholarly environment for the work's completion around 1140, marking canon law's entry into a systematic phase in the modern sense.
4. 1145–1500Paris · ParisFollowing Gratian, the decrees of Pope Innocent III and subsequent decretal collections continued to be supplemented. Universities such as Paris and Bologna trained canon lawyers, and canon law intermingled with Roman law and natural law, profoundly influencing medieval European legal thought and church governance.