The Salvador church was erected on the remains of the Ibn Adabba, the Great Mosque of Muslim Seville (9th century). This religious temple, as well as its surroundings, had great importance in the daily life of the people, which is why when the Christians conquered Seville, they allowed it to be used as a mosque in the beginning, but in 1340, it was converted into the parish of Salvador.
In addition, it was agreed to maintain the ostentatious rank of the second temple of the city; for it was granted a collegiate character. Thus, this building would continue to be used religiously until 1671, when the passage of time left it strongly deteriorated. Its construction as we see it today began in 1674 with the architect Esteban García. Work ended in 1712 under the architect Leonardo de Figueroa.
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.