 Complete the following phrase:  The strategic importance of Eritrea, due to its Red Sea coastline and mineral resources, was the main cause for the federation with Ethiopia, which in turn led to Eritreas annexation as Ethiopias 14th province in 1952. This was the culmination of a gradual process of takeover by the Ethiopian authorities, a process which included a 1959 edict establishing the compulsory teaching of Amharic, the main language of Ethiopia, in all Eritrean schools. The lack of regard for the Eritrean population led to the formation of an independence movement in the early 1960s 1961, which erupted into a 