The events happened on 30th June are :



1934 : Night of the Long Knives : In an event dubbed the “Night of the Long Knives,” Adolf Hitler summarily executed many of his leading SA officials on this day. Founded by Hitler in 1921 and nicknamed the storm troopers or Brownshirts, the SA was a paramilitary group that marched in Nazi Party rallies and carried out unchecked street violence against political opponents. As the SA swelled in size and power, its leadership, headed by Ernst Röhm, harboured aspirations to merge the SA with the regular army and carry out a second Nazi revolution, an idea that was eyed with suspicion by Hitler.



1974 : Soviet dancer Mikhail Baryshnikov defected from the U.S.S.R. while on tour in Canada.



1960 : Zaire, formerly Belgian Congo and now the Democratic Republic of the Congo, declared its independence from Belgium.



1908 : An enormous aerial explosion, presumably caused by a comet fragment colliding with Earth, flattened approximately 2,000 square km (500,000 acres) of pine forest near the Podkamennaya Tunguska River in central Siberia.



1893 : The Excelsior diamond, weighing 995 carats, the largest uncut diamond ever found to that time, was discovered in the De Beers mine at Jagersfontein, Orange Free State.



1859 : Jean-François Gravelet, known as Blondin, crossed Niagara Falls on a tightrope, which was 335 metres (1,100 feet) long and 49 metres (160 feet) above the water.



29th June | 1st July