The rise of the Zagwe Dynasty is the development that helped strengthen Christianity in Ethiopia. The Zagwe Dynasty, which ruled from approximately the 9th to the 13th centuries, is noted for its promotion and consolidation of Christianity as a central aspect of Ethiopian culture and identity. During this period, significant efforts were made to establish Christian churches and monastic communities, and rulers of the Zagwe Dynasty actively supported the Christian faith.
In contrast, the fall of Kush, which had its own religious practices and was predominantly pagan, would not have had the same direct impact on strengthening Christianity in Ethiopia. The failure of the Kushite Kingdom to maintain its influence allowed for the rise of other powers, including the Christian-oriented Zagwe Dynasty.
In summary, the rise of the Zagwe Dynasty was a crucial factor in the growth and establishment of Christianity in Ethiopia.