Twenty five years ago this week, Deutsche Bank made a move that would change it forever and put it on the path to being a global force in investment banking.

The agreement on November 27, 1989 to buy Morgan Grenfell, the merchant bank that was one of the great City of London institutions, for £950 million was one of a string of City takeovers by foreign banks in the decade following the Big Bang that also included Barings becoming part of ING, Kleinwort Benson being taken over by Dresdner Bank and SG Warburg joining the Swiss Bank Corporation family (now UBS).