It is alleged that when Marshal Blücher came to London he was so struck by the wealth of the City that he descended into tears.  “Why so?” he was asked and he replied that it was the thought of looting the City that moved his emotions thus. Wellington was also moved to tears by the casualties at Waterloo  as many other soldiers have since and no doubt will do in the future

Field Marshal Prince von Blücher (1742–1819). Copyright Apsley House / English Heritage.