 When the Vicariate Apostolic of Sudan was established on 3 April 1846, the Congregation of Propaganda selected Knoblecher as one of the missionaries for the region.Before leaving for central Africa he spent eight months in Lebanon and at other places in Syria to acquaint himself with the rites and customs of the Oriental Christians.Towards the end of September, 1847, he left Cairo in company of Maximilian Ryllo, S.J., the Pro-Vicar Apostolic of Central Africa, and four other missionaries, and arrived at Khartoum on 11 February 1848.