Wishing to provide employment opportunities for all twelve sons, Samuel Montagu and his partners decided to open a new bank.
[1][2][3] In The Rise of Merchant Banking, Stanley D. Chapman describes Keyser & Co as a "second eleven" for the numerous sons of the Samuels, Montagus, and the Franklins.
In the early 1970s, the bank, particularly through its managing directors, Roland Franklin and Ian Stoutzker, became very active in corporate finance.
In October 1974, du Cann and the executive of the 1922 Committee met at du Cann's Keyser Ullman offices in Milk Street, where it was decided that the Committee would press Edward Heath to hold a leadership election, which led to Margaret Thatcher becoming party leader.
A Department of Trade and Industry report into the failure of Keyser Ullman found du Cann to have been "incompetent" while chairman between 1970 and 1975.