Thomas Dewar was born in 1864 in Perth, Scotland. The son of John Dewar, Sr., he was exposed at a very young age to the spirit industry in Scotland as his father founded the John Dewar & Sons, Ltd. He earned his education in Perth, as well as in Edinburgh and he soon realised that farming was not his calling.
After his father's death Dewar worked with his brother John A Dewar Jr to continue and grow their family's brand. Gifted with a charisma, Dewar was able to expand his father's business on a global scale.
Leaving his brother in Scotland to run the business, Dewar set out to publicise their brand to the world. Visiting 26 countries over the course of 2 years, the Dewar's brand was put on the map as one of the premier Scotch whiskies available. Dewar kept a journal of his travels which were consolidated and published in the book titled, "Ramble Round the Globe," published by Chatto and Windus in 1894. In 1923 Dewar purchased the Glen Ord Distillery and two years later the Dewar brothers took their company to join the Distillers Company Ltd, both joining the board.
Known as "whisky Tom" he's the longest-staying guest at the Savoy Hotel in London.
Thomas Dewar was active in civic and political life in London: he served on the London county council for West Marylebone from 1892 to 1895, and was Conservative MP for the St George's division of Tower Hamlets in London from 1900 to 1906. He became lieutenant of the City of London.
Knighted in 1902, Dewar received a baronetcy in 1917, and was created Baron Dewar of Homestall in 1919.
During this period, Dewar was noted for his hostility to "pauper immigration" and played an active part in campaigning for the legislation that became the Aliens Act 1905.
Dewar was included as a Knight Bachelor in the 1902 Coronation Honours List of King Edward VII, and was knighted by the King at Buckingham Palace on 18 December 1902. He was created a baronet, of Homestall Manor in the Parish of East Grinstead in the County of East Sussex, in the 1917 King's Birthday Honours List, and raised to the peerage as Baron Dewar, of Homestall in the County of Sussex, in 1919. However, as he never married the baronetcy and barony became extinct on his death, at Homestall, in April 1930, aged sixty-six, following which he was cremated at Golders Green Crematorium.
Thomas Dewar became involved in Thoroughbred horse racing as an owner and breeder. He is best known for two significant horses: Challenger and Cameronian.
Challenger, foaled 1927, whom Dewar bred and raced at age two but who then was sold to American interests after his death. The stallion went on to become the Leading sire in North America in 1939. Bred by Dewar and foaled in 1928, Cameronian won the 1931 Epsom Derby and 2,000 Guineas Stakes.
Dewar created several Challenge Shields for various sports around the United Kingdom and abroad, as well as the Sheriff of London Charity Shield and the Dewar Cup in the United States for Association football.
For cycling he donated the Dewar Challenge Shield in 1901, a heavily embossed silver plaque depicting goddesses and allusions to Scotland to include thistles and a profile of a racing cyclist centrally mounted. It is inscribed; 'Theatrical Sports Five Miles Cycling Championship Shield' – 'Presented by Sir Thomas Dewar MP – To be won Three Years in Succession'. Mounted on a shaped wooden mount, it possesses 14 silver name plaques of winners between 1901 and 1928. The Lord Dewar Challenge Cup was also presented to the Serpentine Swimming Club in Hyde Park in 1925.
For shooting, Dewar presented a trophy for international Smallbore rifle competition as a Postal Match. The Dewar Match is a distributed shooting event held in various locations with the results mailed in to determine an aggregate winner. Dewar's marksmanship trophy is a large silver cup standing over two feet tall with two oversized handles and ornately decorated to the Society of Miniature Rifle Clubs (SMRC) of Great Britain. Engraved upon it, "International Post Trophy Match, Presented by Sir Thomas R. Dewar, Afterwards Lord Dewar, to the Society of Miniature Rifle Clubs For Annual Competition".
Lord Dewar died on 11 April 1930 at his Sussex home, The Homestall, East Grinstead.
A Dewar Challenge Shield, donated by Dewar's granddaughter Alice Dewar, is competed for annually by three rowing clubs in Hammersmith, West London: Furnivall Sculling Club, Sons of the Thames and Auriol Kensington Rowing Club.