Aristocrat and Fife laird; Born April 28, 1918; Died March 14, 2009 John, Baron Bonde, who has died aged 90, was laird of an estate near St Andrews, and possessed ancestry which combined Orkney earls, the Swedish monarchy and the builder of Rosslyn Chapel. His name spelled out his descent: John Anstruther Carl Knutsson Bonde of Charleton, Baron Bonde in the peerage of Sweden; and 21st Lord St Clair, heir of line of the Earls of Orkney.

However, it was his compassion that defined him. In the post-war years, he was involved in attempting to track Nazi war criminals, but his efforts were blocked by members of the Swedish establishment. This hunger for justice arose from his work for three years from 1945 with the Swedish government commission charged with resettling Polish refugees. Possessed of immense charm and diplomacy, Bonde's unassuming manner readily put at ease those from every background. His efforts for Poland were recognised by his award of the Polish Cross of Merit.

Bonde was born in Washington DC, son of Knut, Baron Bonde, a Swedish diplomat. At John's baptism, the Swedish prince who was to become King Gustaf VI Adolf stood sponsor. Raised in London and educated at Eton, John followed his father by studying law at Uppsala University in Sweden. Called up by both the UK and US when war was declared, he had already joined the Swedish cavalry.

Post-war, John Bonde gave up a flourishing career with Esso Petroleum in Sweden when in 1955 he inherited Charleton, the estate near St Andrews where his forebears had been lairds since 1713. He was just fifth proprietor since Waterloo, and settled into the life of a gentleman farmer, supported by his wife Brita, a Finn whom he had married in 1944. Charleton, a Georgian mansion built in the 1740s, was remodelled by Sir Robert Lorimer, including a rare Japanese garden. Years later in another war, the bamboo grown there was transported to London Zoo to maintain the diets of pandas.

Through his father, Bonde held a Swedish peerage. His politician grandfather, Carl Carlsson, speaker in the Swedish parliament, played a leading part in creating independence for Norway in 1905.

By his mother, Grizel Anstruther, he was heir-of-line of the Sinclair Lords St Clair - and would have been 21st Lord St Clair but for the effect of what is held to be a "debatable" attainder against a Jacobite ancestor in 1716. His ancestor William St Clair built Rosslyn Chapel in 1446, regarded by some as the location of the Holy Grail. Grizel inherited Charleton on the death in 1925 of her father Charles. John Bonde succeeded his mother in 1970.

Bonde delighted in playing the piano. His interest in heraldry came through in his accomplishment of needlepoint, sewing on to cushion covers his coat of arms.

Brita Bonde died in 1989, and in recent years Bonde's companion at home and on the golf course had been Lall Tham.

Baron Bonde is survived by his son and two daughters. His son, St Clair Knut Harald Jöns Bonde of Charleton, succeeds to the barony.

GORDON CASELY