Reuters historical calendar - June 20

London, June 19 (Reuters) Following are some of the major events to have occurred on June 20 since 1900: 1900 - The German ambassador in Peking, Baron von Ketteler, was assassinated by Chinese troops as the Boxer Rebellion got under way, seeking to remove foreign influence in China.

1923 - Pancho Villa, Mexican revolutionary leader, was assassinated on his farm.

1940 - The French government requested an armistice with Italy in World War Two.

1944 - The battle of the Philippine Sea ended with Japan losing almost all its remaining trained pilots and at least 4,000 seamen in action against the United States.

1960 - American Floyd Patterson became the first boxer to win the world championship twice when he defeated Ingemar Johansson of Sweden.

1960 - Mali gained independence from France.

1963 - The Soviet Union and the United States agreed to establish a hot-line telephone link; it was opened on August 30.

1969 - In the British colony of Rhodesia (now Zimbabwe), a referendum held on the proposed constitution resulted in a landslide victory for Ian Smith's proposals for a republic.

1997 - Russia pledged to stop targeting Japan with nuclear missiles in a major step to repair uneasy relations with Tokyo.

1999 - NATO Secretary-General Javier Solana said all Serb forces had left Kosovo and NATO's bombing of Yugoslavia had officially ended.

2001 - General Pervez Musharraf, Pakistan's military ruler was formally sworn in as president, removing Mohammad Rafiq Tarar, the figurehead president since Musharraf's seizure of power in 1999.

2002 - A gas explosion tore through a coal mine in the province of Heilongjiang, northeast China, killing 115 people.

2003 - Italy's President Carlo Azeglio Ciampi signed a law providing immunity from prosecution to Italy's top five leaders, halting a bribery trial against Prime Minister Silvio Berlusconi.

2005 - Belgian scientists said they had cloned the first human embryos from unripe eggs matured in the laboratory, a breakthrough in stem cell research.

2005 - Jack Kilby, inventor of the integrated circuit, the basis of the computer chip revolution and foundation of what is now a trillion-dollar industry, died. He was 81.

2006 - Prime Minister Junichiro Koizumi announced Japan would withdraw its troops from Iraq, ending the Japanese military's riskiest and most ambitious overseas mission since World War Two.

REUTERS RJ RK1106