He was born at
Chesterfield on 8 May 1793, the eldest son of Joshua Jebb of
Walton Hall,
Derbyshire and his wife Dorothy, daughter of General
Henry Gladwin of Stubbing Court. His father, a grand-nephew of
Samuel Jebb and
John Jebb (Dean of Cashel), belonged to a family who produced a number of distinguished descendants, and had once had property in England and the West Indies, but he largely lost his wealth. His sister Frances married William Miles (1797–1844), a shipowner and West India merchant, and bought the estate of
Firbeck Hall which was later inherited by his descendants. After passing through the
Royal Military Academy at
Woolwich, Jebb was commissioned as a second lieutenant in the
Royal Engineers on 1 July 1812. He was promoted to first lieutenant on 21 July 1813, and embarked for Canada in the following October. Jebb served with the army under the command of General
Francis de Rottenburg on the frontier of Lower Canada until the summer of 1814, when he joined the army of Lieutenant-general Sir
George Prevost in the United States, and took part in the campaign of the autumn of 1814. He was present at the
Battle of Plattsburgh, 11 September 1814, and was thanked in general orders. His route, however, was not followed by
Colonel By in building the
Rideau Canal; he had chosen a way between
Ottawa River and
Kingston where
Lake Ontario flows into
Saint Lawrence River. Jebb returned to England in 1820, after an extended service in Canada. He was stationed at
Woolwich and afterwards at
Hull until December 1827, when he embarked for the
West Indies. He was promoted second captain on 26 February 1828, and was invalided home in September 1829. Having recovered his health he was sent to
Chatham. Jebb was appointed adjutant of the royal sappers and miners at Chatham on 11 February 1831, and promoted first captain on 10 January 1837. On 10 March 1838 Jebb was appointed by the Lord President of the council to hold inquiries on the grants of charters of incorporation to
Bolton and
Sheffield, and on 21 May of the same year he was made a member of the commission on the municipal boundary of
Birmingham. On 23 November 1841 he received a brevet majority for his past services. ==Prisons==