When the City says 'business' it usually means 'finance' so this library is probably the finest finance library in Europe. Everyone who wishes to achieve anything in life should at least take a look.
This library is one of the very few ugly City buildings. Do not let this put you off as it was simply built at the wrong time. If you are sensitive to such things you may need to take a 'beauty break' by stepping outside for a while.City of London Business Library.