It was founded in 1840 as a chapel of ease "to spare parishioners the long uphill trek [from the foot of Mont Feland] to the ancient Parish Church of St Lawrence"* The renovation was funded by Jersey native Florence Boot, the widow of Jesse Boot, 1st Baron Trent (1850–1931), who substantially grew his father's herbal medicine shop in Nottingham, The Boots Company, into a national retail chain of chemists (U.S. English: "drugstores").
Jersey is one of the Channel Islands, which are British Crown dependencies in the English Channel. They are technically part of the Duchy of Normandy since 933 and not part of the United Kingdom. They suffered harsh occupation by Nazi Germany from June 1940 to May 1945.
*from the church's Web site's About page.