Environmental campaigner and member of the Scottish landed gentry

Born: May 29, 1959;

Died: July 7, 2018

TESSA Tennant, who has died of cancer aged 59, married into the famous and ill-starred Tennant family – her father-in-law was a friend of Princess Margaret, who squandered much of the family fortune and appears as a character in the Netflix drama series The Crown, while her husband came out as gay just a few years after they got married and died of AIDS in the early 1990s.

But Tessa Tennant had a distinguished career in her own right as a campaigner for sustainability and green investment. Although she was in the final stages of cancer, just days before her death she managed to travel from the sprawling estate in the Borders, where she lived, to Holyrood Palace in Edinburgh to be made an OBE by the Queen for her pioneering work in the field of sustainable investment.

The third of four children, she was born Teresa Mary Cormack in Surrey in 1959. Her father was a pilot, who worked for BP. Her mother was the daughter of Lord Davies, a Welsh Liberal politician and philanthropist.

Although she grew up largely in the charming, medieval village of Bletchingley and went to school in Godalming, she enjoyed summer holidays in the Hebrides on Harris, where her parents left her and her siblings very much on their own to explore and have fun. “Free spirit” was a description that would come up time and again during her colourful life.

She studied human environmental studies at King’s College, London. While on a gap year in South America she met Henry Tennant, the charming and handsome son of Colin Tennant, Lord Glenconner, whose great-great grandfather had developed an industrial bleaching process that revolutionised the cotton industry and made him and his descendants very rich.

Tessa and Henry married in 1983 on Mustique, the Caribbean island that Henry’s father had bought and transformed into Party Central for royalty and pop stars and which he would famously leave to one of his servants.

The couple spent time meditating with the Maharishi’s community in Skelmersdale in Lancashire and had a son Euan. Henry subsequently came out as gay, though the couple remained friends and they lived in a family home in London, with their son and a male friend of Henry.

Henry died of AIDS in 1990. His elder brother Charlie was a heroin addict, who died in 1996, and his younger brother had already been incapacitated in a very serious motorbike accident in 1987, leading to tabloid talk of a family curse and leaving Tessa in effective charge of a huge estate in the Borders and what little was left of the family fortune following her father-in-law’s extravagances.

She had worked initially with the Green Alliance think tank and later took on a series of different roles, promoting green investment, trying to persuade financial institutions that sustainability and green investment were not incompatible with profit.

At the same time she attempted to revive the fortunes of the Glen Estate near Innerleithen, renting out cottages, running the farmland and woodland on sustainable principles and promoting the Victorian mansion house and the 3,500-acre estate as a wedding and conference venue and a film location. It was one of the main locations for the 2007 film Hallam Foe with Jamie Bell.

Glen Estate was already well-known in arts and showbiz circles as the Incredible String Band, the only Scottish group to play at Woodstock, had made it their base in the late 1960s and the group’s leader Mike Heron still lives there.

In the late 1980s Tennant had been one of the co-founders of the Merlin Ecology Fund, the first green unit trust in the UK. She was later head of sustainable investment at NPI (the National Provident Institution) and launched its Global Care Asia Pacific Fund.

An unlikely figure, passionate, fast-talking, with an unruly mop of hair, Tennant entered the stuffy, male-dominated world of the boardroom and inspired and converted her listeners with what she had to say.

Local authorities had massive pension funds that were simply handed over to City institutions to invest and she argued that the councils had a moral duty to consider investments in local communities.

Having managed to influence and change thinking in the UK, she concluded that to have a global impact in terms of sustainability she had to take on the even bigger challenge of converting attitudes in Asia. And she did just that, going to meet executives, financiers and directors in Japan, China, Hong Kong and Taiwan and winning them over.

She was chairman of the Carbon Disclosure Project which encouraged corporations and local authorities to assess and publish figures on their environmental impact, a board member of Friends of the Earth UK and an ambassador for WWF UK. And her campaigning helped lead to new legislation requiring pension funds to set out policies on ethical, social and environmental issues.

In 2007 she married for a second time, to Bill Staempfli, an American architect who helped with the ongoing work and plans at The Glen. She discovered she had ovarian cancer in 2012.

When it returned in June last year, she declined treatment.

“I didn’t want the issue to get in the way of work,” she later wrote on her website. She continued with her work for another six months before ill health forced her to stop.

She is survived by her second husband, her son and two grandchildren.