Dr. Pfatteicher, in his book on LBW Commemoratins, uses "apostle to the north" in describing St. Angsar.
St. Ansgar (Sweden) is an Orthodox saint as well as a Western one.So are Sts. Boniface (Germany), Olaf (Norway), Aidan (Britain), Patrick (Ireland), and many others.
St. Sava stands out as a saint of both East and West who lived AFTER both the Great Schism and the brutal 1204 Frankish conquest (called a "crusade") of Constantinople. It seems he was an Orthodox bishop who was nice to the papists in Serbia, too.
Among Lutherans, the "micro-Lutheran" Evangelical Catholic Church has St. Sava in its Kalendar. With the cockeyed elimination of commemorations of Russian saints in the ELCA's feminazi and anti-O/orthodox new hymnal, it's DOUBLY important to remember St. Sava!!!!