Raised in the Church of the Nazarene, a strict Wesleyan Methodist sect, she attended Perth High School and then spent 20 years working in hospitals, including the Bridge of Earn Hospital in Perthshire. It was there she met her first husband, Robin Gloag, while he was a patient and she was a sister on the ward.

They married and started selling caravans with the couple, along with her brother Brian Souter, who went on to bankroll a campaign to stop homosexuality being promoted in schools, buying a bus for £425 in 1980.

They started transporting workers to building sites for a construction company before expanding their fleet with two more vehicles. Cheap tickets between Dundee and London helped get Stagecoach off the ground.

Dame Ann Gloag pictured in 2015. PIC: Andrew Milligan/PA Wire.

By the time Dame Ann, now 80, and her brother stepped back from Stagecoach roles in 2020, it was reported the pair had a combined fortune of £730m.

The rapid expansion of the company took into repeat battles with competition authorities. She previously spoke about acquiring her wealth by ‘fighting for survival’ with her huge financial gains also bringing her into conflict with others.

In 2004, she bought Kinfauns Castle, a 28-acre site at the top of a hill overlooking the River Tay. Substantial renovations included the replacement of a six-foot wire fence, topped with barbed wire, which created a 12-acre enclosure around the property. It was, she said, necessary for the safety of her family given the fear of kidnap, ransom or theft, and the privacy of her high-profile guests.

In the first case of its kind, the local authority and the Ramblers' Association appealed to have a section of the fence taken down under right to roam legislation - but Dame Ann won her claim to privacy.

In 2021, Dame Ann was given permission to open up Beaufort Castle near Beauly as a holiday resort, complete with 50 holiday cabins, despite local protests against the plans.

In her personal life, Dame Ann has been dealt a series of family tragedies. In 1999, her son Jonathan died by suicide, aged 27, and her former husband Robin was killed in a road crash near Perth in December 2007.

Dame Ann’s adopted son Peter, 24, from Kenya, who she adopted in 1995 after she found him starving in a ditch, was paralysed following a road crash in Africa in 2009.

She continues to travel regularly to Africa, where she has set up a number of charities through The Gloag Foundation. Among them is Freedom From Fistula, which she founded in 2008 and helps around 20,000 women and children who have been injured during childbirth.

Dame Ann previously helped establish a hospital in Malawi and founded Kenya Children’s Homes in 2002, which now educates and cares for more than 1,500 children. Her children and grandchildren – she has 13 – have all spent time working in the orphanage, which she has described as a “great leveller”.

In 2019, she was awarded the honour of Dame Commander of the Order of the British Empire by Queen Elizabeth in recognition of her business and charity work.

She is also a signatory to Bill Gates and Warren Buffett’s Giving Pledge, a promise to give at least half their net worth to philanthropy.

Dame Ann said: “If you can take a person out of that misery and you have the ability to do so, surely you would”.

Dame Ann Gloag: From nurse to tycoon with many fights and tragedies in between