According to the 1873 Guide to the Church this memorial was originally sited in the North Transept, an area now largely occupied by the organ. It is believed that the memorial remains in situ behind the organ.
Further Information
Samuel Leggatt (1774-1848) lived in Norwich and was educated at Norwich School and Corpus Christi. He was ordained a priest in October, 1798 and was appointed Chaplain to the Army in 1811. He eventually rose to become the second most senior chaplain in the Army. There is a tablet to his memory in St. Andrew's Church, Norwich, which describes him as "Late chaplain to the Garrison Forces at Portsmouth " and gives his date of death as 7th March, 1848. Samuel does not appear to have married but does seem to have returned to Norwich when he retired.
See also the memorial to Anne Maria Woodhouse, who was the sister of Samuel Leggat.
[Thanks to Hugo Leggatt and David Blake (RAChD) for the additional information. A part of this referred to Leggatt becoming a licensee of the Bell public house after he returned to Norwich but this is refuted by Kay Clearson who says that the publican named Samuel Leggatt was an ancestor of her family and had never been a chaplain.]