(Reuters) - Britain's Queen Elizabeth shook the hand of former IRA guerrilla commander Martin McGuinness for the first time on Wednesday, drawing a line under a conflict in Northern Ireland that cost the lives of thousands of soldiers and civilians.
Here is a look at some of the most significant political handshakes of the last 40 years:
February 21, 1972 - President Richard Nixon makes the first visit by an American president to China, symbolically ending decades of hostility by shaking hands with Premier Zhou Enlai.
March 26, 1979 - Israeli Prime Minister Menachem Begin and Egyptian President Anwar Sadat shake hands at the White House to seal the first peace treaty between the Jewish state and an Arab country.
December 13, 1989 - South African black anti-apartheid leader Nelson Mandela leaves jail temporarily to meet President F.W. de Klerk, their handshake marking the beginning of the end of racist apartheid rule.
June 13, 2000 - The leaders of communist North Korea and capitalist South Korea meet for the first time since Korea was separated in 1948. Kim Jong-il and South Korean President Kim Dae-jung shake hands courteously but with little obvious warmth. Twelve years on, the Cold War standoff on the inter-Korean border continues.
March 25, 2004 - Britain's Tony Blair seals Libya's return to the world community with a handshake with Muammar Gaddafi. Gaddafi was overthrown by his people in 2011.
April 29, 2005 - Taiwanese opposition leader Lien Chan, chairman of the party that ruled China for decades until it was toppled by Mao Zedong's communists and fled to Taiwan in 1949, closes the book on decades of enmity by shaking the hand of Chinese President Hu Jintao in Beijing's Great Hall of the People.
June 2012 - Queen Elizabeth shakes hands with McGuinness in a Belfast theatre, the latest milestone in decades of work to reconcile Catholic nationalists seeking unity with the Irish Republic and Protestant Unionists determined to remain part of Britain.
(Reporting by David Cutler, London Editorial Reference Unit; Editing by Kevin Liffey)