On Thursday, August 23, 1973, Jan-Erik "Janne" Olsson, armed with a semi-automatic gun, walked across Norrmalmstorg (Norrmalm Square) in central Stockholm, the capital of Sweden, and into the Kreditbanken bank.

He made history as he fired a round into the ceiling and yelled: "The party starts! Down on the floor!"

He took four people hostage, demanded money and the release of his partner-in-crime, who was imprisoned at the time. This was the beginning of an incident that would paralyse an entire nation for nearly a week and draw the attention of the whole world. It was also the origin of the phrase "Stockholm syndrome", used to describe the psychological response sometimes seen in an abducted hostage, in which the hostage shows signs of loyalty to the hostage-taker.

That was more than 35 years ago, but Olsson, now 69 and living in northern Thailand, has written his autobiography, giving previously unknown details of the much-studied event. The book, Stockholmssyndromet (Stockholm Syndrome), was published in Sweden last year, and there is an English-language version due in June.