I want to know the answer to the following question:
When was a church first founded at the site?
All the background I'm provided with is that "According to a tradition first reported by Sulcard in about 1080, a church was founded at the site (then known as Thorn Ey (Thorn Island)) in the 7th century, at the time of Mellitus, a Bishop of London.". Is that enough to answer the question?
Answer: yes