Complex sentence: He set up the first university-level school of journalism in Spain at the University of Navarra in 1958, a university under the guidance of the Roman Catholic prelature of Opus Dei, of which he was a numerary member.
Split into simpler sentences: He set up the first university-level school of journalism in Spain at the University of Navarra in 1958. The university was under the guidance of the Roman Catholic prelature of Opus Dei, of which he was a numerary member.