 His call went out to the rulers of Europe, in an agonized plea to turn from internecine warfare to face Christendom's common enemy.Pius entered Mantua on 27 May; his long progress to the place of assembly resembled a triumphal procession.He opened the council on 1 June and waited in Mantua as the guest of Ludovico III Gonzaga until September for the various representatives to assemble.