A team of experts led by Jan Nyssen discovered a historic map of the Horn of Africa. As per Jan’s statement (https://zenodo.org/record/6477453#.YmYmtdpBxPa), the research team have been hinted at the existence of a map prepared by a German atlas printing house in the mid-19th century, as part of their research on historical cartography in the Horn of Africa (Nyssen et al. 2020b; Nyssen et al. 2020a; Nyssen et al. 2019). They indicated the reference below in their report to the map with a scale of 1:5,600,600:
Handtke, F.H., 1849. Nordöstliches Afrika, Ca. 1:5 600 000. In: Sohr, K., Supplement-Band zum Hand-Atlas der neueren Erdbeschreibung, 85. Flemming, Glogau/Głogów and Leipzig [in German]
This historic map clearly shows that Welkait and the rest of Western Tigray, including Abraha Jira and Metema Yohanis belong to Tigray. Further, the map showed that Southern Tigray extends up to Alewuha and beyond.