By Sara Schaefer Muñoz

London bankers were very upset at the U.K.s surprise 2009 bonus tax, but it turns out that J.P. Morgan CEO Jamie Dimon was the most miffed of all.

According to a new memoir by the former U.K. treasury chief, Alistair Darling, of the "crescendo of complaints" about a fresh tax on high-earners bonuses in late 2009, the...