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1866 August 5th. Born at 4 Lister Street, Chorlton upon Medlock the eldest son of William Siddeley, a hosier, and Eliza Davenport, his wife
Educated at Beumaris Grammar School, Anglesey
1891 Living at 35 Acomb Street, Chorlton-on-Medlock: William Siddeley (age 53 born Davenham, Cheshire), a Hosier and Employer. With his wife Eliza Siddeley (age 47 born Altrincham) and their children John D. Siddeley (age 24 born Manchester), a Shirt Cutter; William K. Siddeley (age 21 born Manchester), a Draper's Assistant; Herbert C. Siddeley (age 19 born Manchester), Electrical Engineer's Apprentice; Kate Siddeley (age 17 born Manchester); and Frederick Siddeley (age 7 born Bowdon, Cheshire), Also a lodger Charles Schroeder (age 40 born Germany), a Merchant. One servant.
1892 The young bicycle racer and designer was hired by the Humber Cycle Company.
1893 He moved to Pneumatic Tyre Co managing their factory in Belfast
1894 Birth of son Cyril Davenport Siddeley in Meriden, Coventry
1895 Birth of son Ernest Hall Siddeley (1895-1995)
1896 Formed the Clipper Pneumatic Tyre Co
1898 Birth of son Norman Goodier Siddeley
1898 Formed the Clipper Tyre Co
For publicity, Siddeley became the first person to ride a bicycle from John o' Groats to Land's End.
1901 Living at 150 Birchfield Road, Handsworth, Birmingham: John D. Siddeley (age 34 born Manchester), Managing Director of Pneumatic Tyre Co and Employer. With his wife Sarah M. Siddeley (age 35 born Broughton) and their children Cyril D. Siddeley (age 6 born Coventry); Ernest H. Siddeley (age 5 born Coventry); and Norman G. Siddeley (age 2 born Handsworth). Also his sisters Kate Siddeley (age 27 born Manchester); and Gertrude M. Siddeley (age 21 born Altrincham). Also a visitor Henry W. Bailey (age 19 born Felpham, Sussex), a Civil Engineer.
1902 Siddeley founded the Siddeley Autocar Co, after beginning to import Peugeots from France.
1903 The new firm had Peugeot-based demonstration cars at the Crystal Palace exhibition
1903 Birth of his daughter Nancy Mabel Siddeley (1903-1963)
1904 Birth of his daughter Joan Murray Siddeley (1904-1984)
1904 "SIDDELEY, J. D., 79, York Street, Westminster, London, S.W. Owned his first car in 1899, and has been an enthusiastic motorist ever since. Is a founder member of the Midland Automobile Club, and has been chairman of its committee since its inauguration. Was secretary for the observers at the 1902 September Reliability Trial, and represented the trade on the Trials Organization Committee in 1903. Clubs: A.C.G.B. & I. (Club Committee)." 
By 1905, the company had a dozen models for sale, and it was purchased by Wolseley of Coventry. Siddeley became the manager of the newly-independent company, renaming it Wolseley-Siddeley.
1910 Biographical information and image at Automotor Journal 19100101
1911 Living at Hill Orchard, Meriden, Coventry: John Davenport Siddeley (age 44 born Longsight, Lancs.), a Motor Car Manufacturer and Employer. With his wife (married 18 years with five children) Sara Mabel Siddeley (age 43 born Broughton, Lancs.) and their daughters Nancy Mercer Siddeley (age 7 born Bromley) and Joan Murray Siddeley (age 6 born Bromley). Three servants.
WWI During World War I, Siddeley-Deasy grew to have 5,000 workers producing ambulances and aircraft engines.
1918 Patented a vaporiser for internal combustion engines. 
1918 They moved to Crackley Hall, Kenilworth.
1919 Armstrong Whitworth acquired Siddeley-Deasy which become part of Armstrong Siddeley Motors, the latter company continuing to produce automobiles until 1960. A major success was the Jaguar air-cooled engine, which attracted much government business. Siddeley exploited this by arranging for airframes, including the Siskin 3A, to be designed around the engine.
1927 The parent company had financial difficulties. The aircraft and motors businesses were sold as part of the Armstrong Whitworth Development Co with Siddeley as chairman. Siddeley arranged a bank loan to help with the buy-out. The holding company was then renamed Armstrong Siddeley Development Co. Armstrong Whitworth retained a substantial shareholding in the company. .
1932 He was knighted
1935 Siddeley remained in charge until 1935.
1937 Purchased Kenilworth Castle and the same year he was raised to the peerage as Baron Kenilworth, of Kenilworth in the County of Warwick.
1937-39 President of the SMMT
After his retirement he moved to Jersey
1953 November 3rd. He died at the Bon Air Nursing Home, St Saviour, Jersey, heartbroken by the death of his wife a fortnight earlier.
He was succeeded in the barony by his son Cyril.
1903 Bio Note 
SIDDELEY, J. D.- Born in Manchester in 1866, Mr. Siddeley has been very actively associated with all important events of the Club. He ordered his first car from the Daimler Company in 1899, and in the same year was elected a member of the Club. He took part in the 1000 Miles Trial in 1900, winning the second prize in his class; helped to found the Midland Automobile Club in the same year, and has occupied the position of Chairman of Committee of the same since its foundation. Took part in the Glasgow Trials, was elected to serve on the Motor Servants' Committee of this Club in 1902, on the Club and Executive Committees in June, 1902, elected a member of the Sub-committee on Affiliation and the Motor Union. Mr. Siddeley has acted as Secretary for Observers in connection with the September Reliability Trial of last year, and has been elected to represent the trade as a member of the Trials Organisation Committee of 1903.