Maltese historian Giovanni Francesco Abela states that following their conversion to Christianity at the hand of St. Paul, the Maltese retained their Christian religion, despite the Fatimid invasion. Abela's writings describe Malta as a divinely ordained "bulwark of Christian, European civilization against the spread of Mediterranean Islam". The native Christian community that welcomed Roger I of Sicily was further bolstered by immigration to Malta from Italy, in the 12th and 13th centuries.