The fate of Christianity in the region remains largely unknown. The church institutions would have collapsed together with the fall of the kingdom, resulting in the decline of the Christian faith and the rise of Islam in its stead. Islamized groups from northern Nubia began to proselytize the Gezira. As early as 1523 King Amara Dunqas, who was initially a Pagan or nominal Christian, was recorded to be Muslim. Nevertheless, in the 16th century large portions of the Nubians still regarded themselves as Christians. A traveler who visited Nubia around 1500 confirms this, while also saying that the Nubians were so lacking in Christian instruction they had no knowledge of the faith. In 1520 Nubian ambassadors reached Ethiopia and petitioned the Emperor for priests. They claimed that no more priests could reach Nubia because of the wars between Muslims, leading to a decline of Christianity in their land. In the first half of the 17th century, a prophecy made by the Sudanese Sheikh Idris Wad al-Arbab mentioned a church in the Nuba Mountains. As late as the early 1770s there was said to be a Christian princedom in the Ethiopian-Sudanese border area, called Shaira. Apotropaic rituals stemming from Christian practices outlived the conversion to Islam. As late as the 20th century several practices of undoubtedly Christian origin were "common, though of course not universal, in Omdurman, the Gezira and Kordofan", usually revolving around the application of crosses on humans and objects.