Margaret of Mar, 31st Countess of Mar

When in 1975 her father the 30th Earl died, Lady Margaret became the 31st holder of the Mar earldom, the premier earldom of Scotland, and entered the House of Lords, making her maiden speech in April 1976. After the passing of House of Lords Act 1999, Lady Mar was elected to serve as one of the ninety-two hereditary peers retained in the House, where she sat as a crossbencher, meaning she is not aligned with any particular political party. She retired from the House on 1 May 2020.

In the summer of 1989, while dipping her sheep through a tank of organophosphorous chemicals, Lady Mar was subjected to a splash of chemicals on her foot, and three weeks later developed headaches and muscular pains. She was eventually diagnosed with chronic fatigue syndrome. Since then Lady Mar has used her seat in the House of Lords almost exclusively to press the government to provide suitable care and support for patients with similar long-term and poorly understood medical conditions, and to better regulate the use of organophosphates. This also led to her membership on the EU sub-committees listed above.

When Margaret's father succeeded as 30th Earl of Mar in 1965 she became Lady Margaret of Mar, and her brother became The Master of Mar, Lord Garioch. When Lord Garioch died in 1967, Margaret became The Mistress of Mar as the elder heir-portioner presumptive in general of her father.

Lady Mar has married three times: first to Edwin Noel Artiss, then to John Salton, and finally to John Jenkin. From the first marriage she had a daughter: Susan Helen of Mar, Mistress of Mar (born 1963), the heir presumptive to her mother's peerage. Lady Susan is married to Bruce Alexander Wyllie, and has two daughters, Isabel and Frances.

Margaret had two younger siblings: David of Mar, Master of Mar, and Lady Janet of Mar. In 1959, her father was officially recognised in the style of Mar, and from that year his three children were also styled of Mar, the name Lane being abandoned.

From 1959 to 1962, she was a civil servant with the Ministry of Pensions and National Insurance, before taking a position as a nursing auxiliary at the Bromsgrove Cottage Hospital from 1964 to 1969. She was a sales superintendent for British Telecom between 1969 and 1982, after which she took up farming.

Margaret of Mar, 31st Countess of Mar (born 19 September 1940) is a Scottish hereditary peer and politician. She was a crossbench member of the House of Lords from 1975 to 2020 and was one of 92 hereditary peers elected to remain in the Lords in 1999. She is the holder of the original earldom of Mar, the oldest peerage title in the United Kingdom. She is the only suo jure countess and was the only female hereditary peer in the House of Lords from 2014 to 2020. She is also a farmer and former specialist goats cheesemaker in Great Witley, Worcestershire.

She was born Margaret Alison Lane, the daughter of Millicent Mary Salton and James Clifton Lane, later James of Mar, 30th Earl of Mar, the heir presumptive of Lionel Erskine-Young, 29th Earl of Mar, his first cousin once removed (both were descended from a sister of John Goodeve-Erskine, 27th Earl of Mar).