 Kaloyan, the third of the Asen monarchs, extended his dominion to Belgrade and Ohrid. He acknowledged the spiritual supremacy of the pope and received a royal crown from a papal legate. The empire reached its zenith under Ivan Asen II (1218 – 1241), when commerce and culture flourished. The strong economic and religious influence of Tarnovo made it a "Third Rome", unlike the already declining Constantinople.
