The Kaufmannskirche St. Gregor (Merchant's Church St Gregory) is a 14th-century Gothic parish church at Anger Square. It is one of the largest and most important original parish churches in Erfurt. The parents of Johann Sebastian Bach, Johann Ambrosius Bach and Maria Elisabeth Lämmerhirt married here in 1668.
The former Romanesque building (11th century) on the site was burnt down in 1291. The consecration of the Gothic basilica with twin choir towers took place in 1368. The altar (1625), pulpit (1598), baptismal font (1608), epitaphs (1584/85/90) are works of the Thuringian Late Renaissance and forms of Luther iconography of Erfurt sculptors and stone masons Hans Friedemann, the Elder and Younger. Martin Luther preached here on 22th October 1522.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.