Eritrea used to be part of Ethiopia. Historically and ethnographically speaking, Ethiopia and Eritrea are highly interrelated. Their history goes way back, and it'd be futile (and off the subject here) to go into the details here. read more
The various city states in Tigray, the northernmost region of the new Ethiopia and closely related to the Hamassien of Eritrea, never accepted to be part of the new Ethiopia and some even demanded to be incorporated with Eritrea under Italian protectorate. read more
Eritrea won its independence from Ethiopia in 1991 after a 30-year war. Peace was short lived. From 1998–2000, the two nations waged a major border war; the casualties were estimated to be around 70,000. read more