[2] He became a wealthy man, holding considerable amounts of Bank of England stock.
[1] Between 1748 and 1753 he undertook the Grand Tour with his brother-in-law Sir Matthew Fetherstonhaugh, 1st Baronet, and his step brother Lascelles Iremonger.
[3] Benjamin's sister Sarah Lethieullier (1722–1788), Lady Fetherstonhaugh, also joined the group on their Grand Tour during 1749 and 1751, and was also depicted by Pompeo Batoni (1708-1787).
In 1768 Lethieullier was returned as Member of Parliament for Andover and held the seat for 29 years.
[1] Lethieullier is not recorded as speaking in parliament but voted regularly on major issues.