He entered the employment of the East India Company in 1769, and served as judge-advocate and paymaster during the expeditions against Gujarat and Bharuch in 1771. In the following year he left the service of the company and returned to Europe. Wraxall at their suggestion undertook to endeavour to persuade the king to act on her behalf.
He was able to secure an interview with her at Celle Castle in September 1774.
His exertions are told in his Posthumous Memoirs. As the queen died on 11 May 1775, his schemes came to nothing and he complained that he was out-of-pocket, but George III took no notice of him for some time.
In 1775 he published his first book, Cursory Remarks made in a Tour through some of the Northern Parts of Europe, which reached its fourth edition by 1807, when it was renamed A Tour Round the Baltic. In 1777 he travelled again in Germany and Italy.
As he had by this time secured the patronage of important people, he obtained a complimentary lieutenant"s commission from the king on the application of Lord Robert Manners, which gave him the right to wear uniform though he never performed any military service.
In this year he published his Memoirs of the Kings of France of the Race of Valois, to which he appended an account of his tour in the Western, Southern and Interior Provinces of France. In 1778 he went again on his travels to Germany and Italy, and accumulated materials for his Memoirs of the Courts of Berlin, Dresden, Warsaw and Vienna (1799). In 1780 he entered Parliament and sat till 1794 for Hindon in Wiltshire, Ludgershall and Wallingford, in succession.
He published in 1795 the beginning of a History of France from the Accession of Henry III to the Death of Louis XIV, which was never completed.
Little is known of his later years except that he was made a baronet by the prince regent in 1813. His Historical Memoirs appeared in 1815.
Both they and the Posthumous Memoirs (1836) are very readable and have real historical value. Wraxall believed that the Government of the day, furious at his truthfulness, was behind a libel action which sent him to prison for three months in 1816.
Hence the posthumous publication of the later memoirs.
He died suddenly at Dover on 7 November 1831, whilst travelling to Naples. Wraxall married Mission Jane Lascelles, the daughter of Peter Lascelles, in 1789. Sir F. C. Lascelles Wraxall (1828–1865), was a miscellaneous writer