A brief history - Holy Trinity was built in 1789 and was known then as 'La Chapelle de la Trinite'. Its foundation probably is connected with the visit of John Wesley to Guernsey in 1787 and evangelical Bible based teaching has been maintained ever since the inception of the chapel.
The foundation stone of the building was laid by the then Bailiff of Guernsey - William Le Marchant, and the building was opened on the 5th July 1789 as a propriety chapel (or chapel of ease) to the Parish Church of St Peter Port for the better accommodation of the French congregation. The chapel was erected at a cost of £2,990 and the sale of the pew seats on completion amounted to an income of £3,280.10.0, so the venture was sound!
However, some 57 years later after the congregation had been dwindling for many years, and many pew rents remained unpaid, on the 30th April 1846, the proprietors consented to sell the chapel for £1,200 to the patrons of the future church, the Rt. Rev. Charles Sumner D.D., Lord Bishop of Winchester and 5 other gentlemen who became the first Trustees.
The 15th June 1846 saw the completion of the purchase of the church by the Trustees from the Elders of Trinity Chapel and on the 4th August 1846 the church was consecrated and dedicated to the Holy Trinity by the Lord Bishop of Winchester. The first Vicar was the Rev. Robert W.Kyle. Since then there have been 17 ministers including the present vicar, Jon Honour. The longest serving Vicar was the Rev. Nassau Cathcart who held the incumbency for 52 years (1861-1913).