German Chancellor Angela Merkel signs the condolence book for Margaret Thatcher at the British Embassy in Berlin on Thursday. The former British prime minister died of a stroke on Tuesday at the age of 87. Following the death of the "Iron Lady," Merkel, who is also sometimes called the "Iron Chancellor" in the media, described Thatcher as "one of the greatest leaders of her time in global politics." One of her greatest convictions, Merkel said in a statement, was that of individual liberty. "Margaret Thatcher was quick to recognize the strength of the protest movements in Eastern Europe demanding more freedom, and she gave them her full support. I will never forget the part she played in reuniting Europe and ending the Cold War."