Bulgarian opera singer, widely considered one of the greatest basses of the 20th century. In the late 1930s he graduated in law and started a career as a magistrate. He continued singing in his spare time in the Gusla Chorus in Sofia, achieving an enormous success as the chorus soloist in 1940. Thanks to a government grant, Christoff left in May 1942 for Italy where he was tutored for two years in the core Italian bass repertoire by the great baritone of an earlier generation, Riccardo Stracciari. He made his operatic debut as Colline in La bohème at Reggio Calabria on 12 March 1946. In following years Christoff appeared in a number of roles at Milan's La Scala, Venice's La Fenice, the Rome Opera, Covent Garden in London, the opera theatres in Naples, Barcelona, Lisbon, Rio de Janeiro, etc.