Pope Benedict XV promulgates the 1917 Code of Canon Law, the first comprehensive codification of Catholic canon law in the legal history of the Catholic Church.

Pope Benedict XV was head of the Catholic Church from 1914 until his death in January 1922. His pontificate was largely overshadowed by World War I and its political, social, and humanitarian consequences in Europe.

The 1917 Code of Canon Law, also referred to as the Pio-Benedictine Code, is the first official comprehensive codification of Latin canon law.

In law, codification is the process of collecting and restating the law of a jurisdiction in certain areas, usually by subject, forming a legal code, i.e. a codex (book) of law.

The canon law of the Catholic Church is "how the Church organizes and governs herself". It is the system of religious laws and ecclesiastical legal principles made and enforced by the hierarchical authorities of the Catholic Church to regulate its external organization and government and to order and direct the activities of Catholics toward the mission of the Church. It was the first modern Western legal system and is the oldest continuously functioning legal system in the West, while the unique traditions of Eastern Catholic canon law govern the 23 Eastern Catholic particular churches sui iuris.

The Catholic Church utilizes the oldest continuously functioning legal system in the West, much later than Roman law but predating the evolution of modern European civil law traditions. The history of Latin canon law can be divided into four periods: the jus antiquum, the jus novum, the jus novissimum and the Code of Canon Law. In relation to the Code, history can be divided into the jus vetus and the jus novum. Eastern canon law developed separately.