Mr Souter speaks with a strong Scottish accent and has a penchant for red blazers which make him look like a maitre d' in a Beefeater restaurant. But behind the unfashionable attire and the slightly uncomfortable public manner, there is a sharp financial brain.
Mr Souter is the son of a bus conductor and worked as one himself, but he always set himself higher goals. His bus work was only to pay his way through a chartered accountancy course at Strathclyde University and he soon joined accountants Arthur Andersen.
Mr Souter and Ms Gloag, who were brought up in a council house in Perth, used their father's pounds 25,000 redundancy cash to set up their own business in 1980, starting with two second-hand coaches running between London and Dundee.
The subsequent growth of the company has been motivated by Mr Souter's hard work ethic and he has clearly been uncompromising in the pursuit of his business objectives. You don't go from nothing to more than pounds 500m in 15 years without a tinge of ruthlessness, but this has been tempered by his strong Christian beliefs.
He is an evangelical Christian who neither smokes nor drinks. While his workforce are expected to do long hours, the company does recognise unions and one trade unionist said that Mr Souter was "someone we can do business with".
Ms Gloag, 12 years Mr Souter's senior and now aged 53, had an inglorious academic career, failing to get any O levels. She became a nurse after leaving school, but when she was unable to cope on a nursing sister's income, she and her brother started renting out caravans and minibuses as a part-time supplement to her income.
Given the paucity of successful businesswomen, it is hardly surprising that she was voted Businesswoman of the Year in 1990. Through her efforts, Stagecoach runs the main bus service in Malawi, has acquired a company in Kenya, runs services in Wellington, New Zealand, and has set up an office in Hong Kong.
Described as "friendly and unflashy" in one profile, she does not like publicity and recently complained to a television company which hired a helicopter to overfly her castle. Unfortunately for Ms Gloag, with Stagecoach rarely out of the public eye and businesswomen still so rare, she may find it increasingly difficult to steer clear of the spotlight.Reuse content