Born in 1859, the son of the Rev Thomas George Messervy of Coie Terrace and Estelle Francoise Guillaume, J A Messervy, as he was always known, was educated at Victoria College from the ages of 10 to 18 and then went to a College in Vire, Calvados, and subsequently university in Caen. He followed his father in becoming a Minister in the Reformed Church in Normandy and in 1893, a year before returning to Jersey, he married Carolina Leonie Auguste Quirin, daughter of another Minister, Frederic Auguste Quirin. He is described in the 1901 census as a 'retired clergyman'.
He became Librarian of La Société Jersiaise and editor of its Bulletins and publications. He died in 1921 after becoming by far the most prolific historical researcher and writer in the early Société Bulletins. He worked very closely with his wife, who was known as Auguste, and she continued publishing some of his work after his death in his name, and also in her own name, although the style of writing suggests strongly that he might have been the original writer of all of the publications.
Messervy wrote a series of Bulletin articles under the heading Notices sur Quelques Anciennes Familles Jersiaises.
There were 33 published articles in total, but Messervy appears to have researched many more, books of his research notes surviving in the Société Jersiaise Library.
- History of Guerdain family in Jersey
- History of De La Rocque family
- History of Sarre family in Jersey
De la Rocque, de Soulemont, de Rue, de Carteret (1535 onwards), Journeaux, Le Breton, Romeril, Hue, Falle of Maufant, Fondan of St Peter, Robin, Jutize, Patriarche were gathered together in a bound book by G T Messervy (possibly a son or grandson) and eventually donated to the Société. The book also has the title Notices sur Quelques Anciennes Familles Jersiaises but the pages are simply extracted from original bulletins, not reprinted, and there may have been just the one family copy.
There are further separate booklets by Messervy, giving histories of the Lemprières of Dielament, the Payn family of St Lawrence and the de Gruchy famly.
- Messervy genealogy collection in the Société Jersiaise Library: Containing a list of notebooks of families researched for some of the articles above, and a substantial number for which no published works appear to exist Added 2018
Messervy’s many other articles include lists of rectors for various churches, lists of Bailiffs, Lieut-Bailiffs and Juge Delegues, lists of Attorney-Generals and Jurats. These have been widely copied and versions can be found on the internet, with no attribution to Messervy. They form the basis for similar listings in Jerripedia, which have also reverted to Messervy's main source in the French archives, and have been updated with later amendments and additions made by Messervy himself and further information which has come to light in the past 100 years.