 In 1444 and again in 1448 Juan Carvajal was sent to Bohemia to promote the cause of religious unity; but he failed both times, owing to the stubbornness of the Calixtines or Utraquists and the influence of the Calixtine John Rokyczana, who had been declared Archbishop of Prague by Sigismund, the Holy Roman Emperor and King of Hungary.Rokyczana, whose orthodoxy was suspected at Rome, was never approved by the Pope however and, from Rome's point of view, the Archdiocese of Prague was vacant from the death of Conrad de Vechta in 1431 until 1561.Pope Eugene died on 23 February 1447.