Altar of Pope Leo the Great
St. Peter's Basilica
Vatican City
Rome Italy
2016

https://www.walksinrome.com/altar-of-pope-leo-the-great-st-peters-basilica.html

Altar of Pope Leo the Great (1640-53) by Alessandro Algardi
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The altarpiece, the only one in St Peter's to take the form of a marble relief, is the work of Alessandro Algardi (1598-1654). It depicts Pope Leo I invoking the intervention of St Peter and St Paul to prevent Attila the Hun from attacking Rome.

Leo the Great (r. 440-61) was the first pope to be interred in the old basilica. His remains were moved to the new basilica by Pope Paul V (r. 1605-21). Leo I is one of the few popes to have been granted the title 'Great'.

https://www.walksinrome.com/a-guide-to-st-peters-basilica.html

St. Peter’s Basilica is the largest church in the world. It stands above the spot where St Peter is thought to have been buried. The basilica is the second church to have been erected here; the first was built by Emperor Constantine the Great (r. 306-337) between 324 and 329.