This rite was in union with the Assyrian (Chaldean) church which had fallen into the Nestorian heresy after the Council of Ephesus in 431. This church was "discovered" by Portuguese missionaries ...

A Church sui iuiris is a distinct community of faithful within a rite of the Church ... one Armenian, two Chaldean and 14 Byzantine. Information on each of these sui iuris Churches as well ...