Citigroup announced its intentions to become a leading force in European investment banking a decade ago when it paid £1.3bn for blue-blooded UK merchant bank Schroders.

The history of investment banking mergers is littered with failure as the collision of opposing cultures led to disharmony and destroyed value. Around the same time, Credit Suisse First Boston bought Donaldson, Lufkin & Jenrette for $12bn in cash and spent the following years regretting it as the guaranteed compensation packages paid to the DLJ bankers destroyed trust within the firm.