Complex sentence: Emmanuel Amand de Mendieta (1907--1976) was a Belgian Benedictine scholar specialised in the works of St. Basil of Caesarea, of Belgian aristocratic descent, attained a brief prominence in the English-speaking world through his passage to Anglicanism in 1962.
Split into simpler sentences: Emmanuel Amand de Mendieta (1907--1976) was a Belgian Benedictine scholar who specialised in the works of St. Basil of Caesarea. Of Belgian aristocratic descent, he attained a brief prominence in the English-speaking world through his passage to Anglicanism in 1962.