A decade ago, Deutsche Bank faced a barrage of questions from sceptical investors and journalists as it closed in on the $10bn acquisition of US investment bank Bankers Trust.

The scepticism was well founded. In 1989, Deutsche Bank had bought the venerable London investment bank Morgan Grenfell and, after a promising start, spent DM3bn between 1994 and 1997 hiring top Wall Street bankers to expand the business.