Complex sentence: It is the first known appearance linking Morgan to Igraine and mentioning her learning sorcery after having been sent away for an education; she masters seven arts and goes on to specialize in "astronomie" (astronomy and astrology) and healing.
Split into simpler sentences: It is the first known appearance linking Morgan to Igraine and mentioning her learning sorcery after having been sent away for an education. There, Morgan begins her study of magic arts, mastering seven arts and goes on to specialize in "astronomie" (astronomy and astrology) and healing.