Bulgaria–United States relations to work. Bulgaria became a member of the Warsaw Pact on May 14, 1955. Though no Soviet troops were stationed on Bulgarian soil, in 1968, Zhivkov sent a Bulgarian division to join Polish, Hungarian and Soviet troops to crush a popular uprising in Prague. In 1978, the Bulgarian secret police were implicated in the assassination in London of Georgi Markov, a Bulgarian dissident who was a correspondent for the BBC World Service, Deutsche Welle radio and the U.S. sponsored Radio Free Europe. Markov was assassinated with a poisoned umbrella on September 7, Zhivkov's birthday. The rise of democratic movements across
Death on the Nile (1978 film) pythons. Cinematographer Jack Cardiff says he and Guillermin decided to give the film "an old fashioned 30s look". The choreography for the tango scene was provided by British dancer Wayne Sleep. In early 1978 David Niven's daughter was seriously injured in a car accident. Niven would fly from London to Switzerland on weekends during filming to sit by her bedside. Although it was a British film, "Death on the Nile" first premiered in New York, on 29 September 1978, to coincide with the sale of tickets for the Metropolitan Museum of Art's opening on 15 December 1978 of the travelling