Jimmy Marr was a local historian who combined his passion for historical research with a deep love of his native island in his writings on island topics. Foremost among his publications was his History of Guernsey, hailed as the most important book on the Bailiwick since Tupper's history more than a century earlier.

Although living in England, in Hornchurch, Marr was a frequent visitor to Guernsey, making a carefully planned pilgrimage at least twice a year. In his more active days he would trek the length and breadth of the island — indeed all the islands of the Bailiwick — with his friends and fellow local historians, Carel Toms, Victor Coysh, and Stanley Kellett-Smith. He would explore extensively and in the minutest detail, delighting as much in the discovery of a hitherto unseen cattle trough as in the grandeur of the south-coast cliffs.

Leonard James Marr was born in 1918 at the family home in Les Canichers, St Peter Port, the son of Leonard and Elvina (née Machon) Marr. He was brought up in Guernsey and, in his short book, Guernsey Between the Wars: An Islander Recalls his Youth, he left an affectionate account of the island of his boyhood.

A grandfather, Alfred Machon, was an antique dealer and cabinet maker, having premises in Le Pollet (now Machon’s, the jewellers), and a great-grandfather, William Le Poidevin, established the grocery shop at 26 Cornet Street, now restored and preserved by the National Trust of Guernsey.

Marr was educated at the Intermediate School and Les Vauxbelets College before going to the College of St Mark and St John in London, from which he graduated in economics and political science. He was grateful for the strict but compassionateatmosphere of Les Vauxbelets, and his his schooling had a profound influence on his Christian beliefs. During his time he saw the building of the Little Chapel. In later years, he remained friends with Brother Christantian and Father Chauvel.

The beginnings of Marr’s teaching career, at St Sampson’s School in the late 1930s, were interrupted by the outbreak of war. He joined the British Army at the Town Arsenal at the first opportunity, returning to Guernsey in 1940 on special leave to persuade his mother to go to England. He subsequently served in France, North Africa, Italy and Austria. After the war he taught at Hackney Downs, the London school founded by the Grocers' Company. Frmer pupils remembered him as an inspiring and courteous teacher.

He retired from teaching in 1978 and set to work on researching and writing his Guernsey history. He was an enthusiastic supporter of the Guernsey Society, the organisation founded in London in 1943 to enable islanders to maintain contact with each other during their exile.

Living, as he did, away from his native isle, he was immensely proud of his roots, giving talks on Guernsey's history to members of the society, and writing articles for The Review until within a few months of his death. He was elected to the society's council in April 1980 and two years later took on the duties of public relations officer and auditor. In 1988 he became honorary editor of The Review, a post he held until May 1993. In May 2005 he was elected vice-president in recognition of the contribution he had made to the society over the years.

His articles in The Review and elsewhere were carefully researched and related with great enthusiasm. Having alighted upon a previously unnoticed aspect of a medieval event, he would describe the discovery with all the urgency of an event happening right now. This enthusiasm for his subject could spill over into boyish glee if he discovered an inaccuracy in some learned book.

His books on historical aspects of Guernsey include: The History of Guernsey – The Bailiwick's Story; Guernsey People; More People in Guernsey's Story; Bailiwick Bastions; Bailiwick Harbours and Landing Places; and Guernsey Between the Wars – An Islander Recalls his Youth. He also wrote a fictional trilogy, Two Men and a Woman, set in the island.

Marr was a devout Anglo-Catholic, attending St James Garlickhythe in the City of London, and latterly when unable to travel, St Mary Magdalene in Ockendon. When in Guernsey, he worshipped at St Stephen's Church.

He was a man who always had lots to do: researching, writing, campaigning on issues he felt passionate about.

Marr married first, in 1940, Marian Collyer, with whom he had a daughter. Marian died in 1956, and he married second, in 1957, Constance King, who died in 2005.