Ana Botín Faces Her Biggest Test at Santander

With her appointment as chief executive officer of Banco Santander's (STD) U.K. unit in November, Ana Patricia Botín has a chance to prove she should succeed her father, Emilio Botín, 76, as chairman of Spain's largest bank. All she has to do is repair the bank's customer-service reputation and pull off an initial public offering.

London will be the toughest test yet for Botín, 50, whose performance is being closely watched in Spain, where Botíns have helped manage Santander for 115 years. She took charge of Britain's second-largest mortgage lender after former U.K. head António Horta-Osório defected to lead rival Lloyds Banking Group (LYG).