Which Pope's reign is associated with the establishment of earlier church burial customs?

The reign of Pope John III is notable for its association with the establishment of earlier church burial customs. During his papacy, which lasted from 561 to 574, he played a significant role in formalizing practices related to how the deceased were treated and prepared for burial within the context of Christian beliefs. This was a period when the Christian Church was in the process of creating structured rituals and guidelines surrounding death and burial, reflecting a growing concern for the dignity of the deceased and the importance of proper rites in accordance with Christian theology.

In contrast, the other popes listed, including John Paul II, Benedict XVI, and Francis, while influential in their own rights regarding various contemporary issues in the Church, do not have their reigns specifically tied to the foundational establishment of burial customs in the way that Pope John III does. Their focus may have been on modernizing the Church, addressing moral issues, or engaging with social justice, rather than the historical development of burial practices.