Mengesha Yohannes (1868 - 1906) was the natural son of Emperor Yohannes IV of Ethiopia, Ras of Tigray, and as a claimant of the Imperial throne is often given the title of prince. He was acknowledged as son and designated as heir by Yohannes IV on his deathbed at the Battle of Metemma. Fighting between various relatives of the slain Emperor split his camp and prevented Mengesha from making a viable bid for the Imperial throne, and the throne was assumed by Menelik of Shewa. Ras Mengesha refused to submit to Menelik, and later even flirted with joining the new Italian colony of Eritrea, hoping that they would support his rebellion against Emperor Menelik. However, encroachments by the Italians into his native Tigray, their previous enmity to his father Yohannes, and recognition that their ultimate goal was to conquer Ethiopia led him to finally submit to Menelik II, and to fight at his side against them at the Battle of Adowa.

Ras Mengesha was married to Woizero Kefey Welle, the niece of Empress Taytu Betul. He rebelled again against Menelik when he was denied the title of Negus of Zion. (His descendants would be outraged decades later when Ras Mikael was crowned with this title by Lij Iyasu). Emperor Menelik had Ras Mengesha captured and imprisoned under house arrest at the old Shewan royal palace at Ankober. Familial rivalry between the two lines of descent from Emperor Yohannes IV (through his elder legitimate son Ras Araya Selassie Yohannes and his younger natural son Mengesha) proved to be a difficult issue for Emperor Menelik II and his successors. Ras Araya's son Gugsa, and Ras Mengesha's son Seyoum would for a time divide Tigray between them, with Ras Gugsa ruling the eastern half, and Ras Seyoum the western half. Eventually Mengesha's son Ras Seyoum Mengesha was made prince of all Tigray in succession to his father after the death of his cousin Ras Gugsa Araya, and the treason of Gugsa's son, Dejazmatch Haile Selassie Gugsa, who joined forces with the Italian occupiers in 1936. Ras Mengesha is thus regarded as the founder of one of the two senior cadet branches of the Ethiopian Imperial Solomonic Dynasty.