Nelson Mandela was born on July 18, 1918, in Mveso, Transkei, South Africa. Becoming actively involved in the anti-apartheid movement in his 20s, Mandela joined the African National Congress in 1942. For 20 years, he directed a campaign of peaceful, nonviolent defiance against the South African government and its racist policies. In 1993, Mandela and South African President F.W. de Klerk were jointly awarded the Nobel Peace Prize for their efforts to dismantle the country's apartheid system. In 1994, Mandela was inaugurated as South Africa's first black president. In 2009, Mandela's birthday (July 18) was declared "Mandela Day" to promote global peace and celebrate the South African leader's legacy. Mandela died at his home in Johannesburg on December 5, 2013, at age 95.

Winston Churchill's life was a trajectory of events leading to his stand against Adolph Hitler's threat to control Europe. After the Japanese attack on Pearl Harbor, Churchill helped lead a successful Allied strategy with President Franklin D. Roosevelt and General Secretary Joseph Stalin during WWII to defeat the Axis powers and craft post-war peace. After the breakdown of the alliance, he alerted the West to the expansionist threat of Soviet Communism.

Martin Luther King Jr. was born on January 15, 1929, in Atlanta, Georgia. King, both a Baptist minister and civil-rights activist, had a seismic impact on race relations in the United States, beginning in the mid-1950s. Among many efforts, King headed the SCLC. Through his activism, he played a pivotal role in ending the legal segregation of African-American citizens in the South and other areas of the nation, as well as the creation of the Civil Rights Act of 1964 and the Voting Rights Act of 1965. King received the Nobel Peace Prize in 1964, among several other honors. King was assassinated in April 1968, and continues to be remembered as one of the most lauded African-American leaders in history, often referenced by his 1963 speech, "I Have a Dream."

Born on October 13, 1925, in Grantham, England, Margaret Thatcher became Britain's Conservative Party leader and in 1979 was elected prime minister, the first woman to hold the position. During her three terms, she cut social welfare programs, reduced trade union power and privatized certain industries. Thatcher resigned in 1991 due to unpopular policy and power struggles in her party. She died on April 8, 2013, at age 87.

John Fitzgerald Kennedy was born on May 29, 1917, in Brookline, Massachusetts. Both the Fitzgeralds and the Kennedys were wealthy and prominent Irish Catholic Boston families. Kennedy's paternal grandfather, P.J. Kennedy, was a wealthy banker and liquor trader, and his maternal grandfather, John E. Fitzgerald, nicknamed "Honey Fitz," was a skilled politician who served as a congressman and as the mayor of Boston. Kennedy's mother, Rose Elizabeth Fitzgerald, was a Boston debutante, and his father, Joseph Kennedy Sr., was a successful banker who made a fortune on the stock market after World War I. Joe Kennedy Sr. went on to a government career as chairman of the Securities and Exchange Commission and as an ambassador to Great Britain.

David Cameron, a descendant of King William IV, was born into a wealthy British family. He received a quality education, and excelled in his studies at a young age. Once he became head of Britain's Conservative party, Cameron sought to modernize it and shed its right-wing image. Dazzling the party and the populace with his bold eloquence, Cameron positioned his party well for the general election of 2010, and when Gordon Brown resigned as prime minister, Cameron replaced him.