By 1790, when he began to buy landed property on a large scale, Baring was a leading figure in the London commercial world and an acknowledged expert on matters of trade and finance. The family financial house was firmly established, with a growing international reputation, and Baring was leader of the City interest in the East India Company.
His basic political loyalty was to the 1st Marquess of Lansdowne, with whom he had supported government on the Regency question. In 1789 he paid Samuel Smith II £1,500 for a seat for Ilchester at the next general election, but Smith lost control of the borough in the interim and Baring was defeated at the poll in 1790. As chairman of the East India Company in 1792, he was critical of Dundas’s terms for the renewal of the charter and persuaded the minister to modify them. His baronetcy, conferred in 1793, was seen as a reward for his services at East India House. The French wars brought handsome profits to Baring who, on his own and the firm’s account, took a prominent part in the marketing of government loans. In 1795 he began to exploit the opportunities offered by trade with America, where he already had a footing, and the firm’s American business expanded rapidly and rewardingly.
Baring re-entered the House after successfully contesting Wycombe on Lansdowne’s interest at a by-election in 1794. At the general election of 1796 Lansdowne brought him in for Calne and in 1802 he stood again for Wycombe, probably on Lansdowne’s recommendation (though the marquess had sold his property there), was returned unopposed and went on to establish a family interest of his own. He continued to follow Lansdowne’s political line, voting consistently, though irregularly, with the Foxite opposition to Pitt. He cast at least six votes against the war which he was helping to finance and voted against the suspension of habeas corpus, 16 and 17 May 1794, and for Fox’s motion on the state of the nation, 24 Mar. 1795. He spoke against the naval augmentation plan as injurious to shipowners and merchants, 2 Feb., and cavilled at the size of the sum to be raised in new taxes, 23 Feb. 1795. He criticized the financial transactions involving Boyd, Benfield and Company, 5 Feb., 7 Dec. 1795, but according to Joseph Jekyll, who described him as ‘wise, well informed and sagacious’, though ‘apprehensive and inactive in the House’, threw ‘cold water’ on his plan to make a major attack on the Hamburg bill transaction, in which Pitt was implicated.
Baring obeyed Lansdowne’s request that he attend the House to support Manners Sutton’s motion on the Prince of Wales’s claims to duchy of Cornwall revenues, 31 Mar. 1802, but was forced by illness to leave before the division.
These were his last recorded votes and his parliamentary activities seem virtually to have ceased, probably because of declining health, though he was appointed to the select committee on East Indian affairs, 8 May, and listed as ‘Opposition’ in the government list of July 1805. He seems to have retired from active business in February 1806, but may have remained as a sleeping partner in the firm until 1809. He was evidently sympathetic to the ‘Talents’ and in his last reported speech, 17 June 1806, he supported the American intercourse bill. His support for government’s attempt to secure Lauderdale’s appointment as governor-general of Bengal was thought by some observers to be motivated by his desire for a peerage; and a later tradition has it that the patent for his elevation was in preparation when the ‘Talents’ fell.
Baring was probably the most successful and certainly the most prestigious financier of his day. Farington described him as ‘a cheerful man and perfectly unassuming’ and Lord de Dunstanville as ‘the true English merchant’, with ‘large and liberal principles and no unreasonable ambition’. His annual income in his later years was reckoned to be £80,000 and on his death, 11/12 Sept. 1810, he left a private fortune of at least £500,000.