In about 1560 he started upon his major work, the "Survey of London". His antiquarian interests attracted suspicion from the ecclesiastical authorities as a person "with many dangerous and superstitious books in his possession", and in February 1569 his house was searched. An inventory was made of all the books at his home, especially those "in defence of papistry", but he was able to satisfy his interrogators as to the soundness of his Protestantism. A second attempt to incriminate him was made in 1570 also without success.