In July 1961, at a party at Cliveden, home of Viscount Astor, John Profumo met Christine Keeler, a 19-year-old model with whom he began a sexual relationship. The exact length of the affair between Profumo and Keeler is disputed, ending either in August 1961 after Profumo was warned by the security services of the possible dangers of mixing with the Ward circle, or continuing with decreasing fervour until December 1961. Since Keeler had also had sexual relations with Yevgeny Ivanov, the senior naval attaché at the Soviet Embassy, the matter took on a national security dimension.