Leo the Great

Leo I

Lived

c. 400–461

Era

The fathers

Where

Rome

Tradition

The apostolic communities

The Tome that Chalcedon adopted, and a meeting with Attila

Bishop of Rome through the collapse of imperial authority in the west, who found himself doing the work of a government because there was no longer one.

Why it matters

His Tome, a letter setting out that Christ is one person in two natures each keeping its own properties, was read at Chalcedon in 451 and substantially adopted — the single largest contribution any western bishop made to the ecumenical councils. He also went out to meet Attila in 452 and the Huns turned back, and negotiated with Genseric in 455 to limit the sack of Rome to plunder. He argued the Roman see's primacy more systematically than anyone before him, which is one of the roots of 1054.

In the record

1. 451 AD Division

   Council of Chalcedon

   His Tome was read out and substantially adopted

All the figures, from the apostolic age to the present, or the timeline they stand in.