Army of the Ethiopian Empire Armies of the Ethiopia have existed since earliest times . Ethiopia maintained a sizable contingent of her forces in her Sabbean Garrisons which expanded out to project power over colonies in Yemen and to protect Caravans or trade routes . At home Ethiopian Forces under the command Prince Nastesen ( Iskindr ) inflicted a humiliating defeat on the Persian Army of Cambyses . The Prince had been Ordered by His Mother the Candace to draw the Persian Forces deep into Ethiopian territory before engaging them . He did this so well that Cambyses Army was never able to recover and those let alive had to retreat back to Egypt . Cambyses did not attempt to reconquer Ethiopia . About the 2nd century AD , there arose the Axumites rapidly supplanting the Damot . The Axumite however paid homage to their former masters . The Judaic rulers of Damot were held in the highest esteem by the new Axumite Empire . There is evidence in inscriptions and archaeological finds that attest to the presence of Axumite troops in Yemen as early as AD 200 . This suggests that Axum was no less involved in the Arabian matters than Damot during the reigns of GDRT , and his successors ` DBH and Sembrouthes , During the reign of Ousanas , Ezanas father , Axum traded and projected its influence as far as India , where coins minted in Ousanas ' reign were discovered in 1990 . This lasted until the 4th century when Twin Axumite Emperors Ezana and Sezana became converted to the new Chritian Faith . Axum ' s Armies were launched into the former tributary Kingdom of Nubia devastating it to the point it never recovered its former glory or was ever an independent polity again . In 520 , during the reign of Emperor Kaleb Ella Atsbeha , Axum received an appeal from the Eastern Roman Emperor Justinian . At first Axum re - occupied an abandoned fort at Najran with cavalry troops admonshing the local ruler Yusuf Hathar who as a consequence of his conversion to Judaism and the urging of the Persian Sassanian Kings had vigorously undertaken the persecution of Christian pilgrims . Axum was not a new power there Yusuf Hathar who had taken the throne name of Dhu Nuwas may have genuinely been mollified by his actions . The elderly commander Arayat , the uncle of the Emperor , led a company of cavalry into Najran charged with protecting Christian pilgrims on the road to Jerusalem from Banditry . However , peace proved fleeting : perhaps as a result of encouragement from the Persians else out of humiliation Dhu Nuwa ' s men attacked the Fort of Najran . What happened afterward is debated . By some accounts the garrison fought back and died . Witness later accused Dhu Nuwas of having killed the soldiers in their sleep and then massacring all others who had sought their protection . Dhu Nuwas may have believed , and perhaps even received assurances , that the Sassanians would protect his fledgling empire with a sizable force . It is doubtful if he knew that Aryat led the Garrison that he would kill the Emperor ' s uncle without knowing with certainty that Kaleb would exact revenge . It was said that Emperor Kaleb received news of the massacre and the death of his beloved uncle as he was coming out of the Church . He ordered the entire court back into Church and ordered the priests to give the assembled nobles and soldiers including himself the last rites of the Christian faith . He ordered the entire Imperial host to war . The first attempt at crossing was not successful : the army unable to land was forced to return to Adulis . The second embarked via the port of Zeila in present day Somalia , then an Ethiopian port , and dropped anchor in the Yemeni port of Mukwha . Under the command of its Emperor Abraha the Axumite Army of spearmen , swordsmen , elephants , cavalry and Archers defeated the Army of Himyar . It was apparent that Kaleb had not gone there just to punish a wayward vassal . Holding a trial for Dhu Nuwas , Kaleb gave Dhu Nuwas to his own people so they may exact their own justice . He appointed a local Christian named Safwa administrator , left Abraha , his cousin , in charge of the sizable portion of the Axumite Host and returned home to Axum with the rest . The target was an usurper , Yusuf Hathar that had begun to make a name of himself consolidating power in the region . A recent convert to Judaism , he had become a client of the Sassanian Persians , avowed enemies of the Western Roman Empire . appealed for the Ethiopian Emperor . Ethiopian Imperial Army existed in one form or another since the founding of the Ethiopian Empire in the 13th century . During the First Italo – Ethiopian War , the Army of the Ethiopian Empire was able to defeat the army of the Kingdom of Italy at the battle of Adwa . During the Second Italo - Abyssinian War , the Army of the Ethiopian Empire consisted of the Imperial Bodyguard , a central army , and several armies of provincial forces . The Ethiopian army was defeated soundly , after giving considerable difficulty to the Italians . The Italians employed mass aerial bombing of mustard gas to win the Battle of Amba Aradam . On 12 September 1974 , a committee of low - ranking military officers and enlisted men called the Derg deposed Emperor Haile Selassie . The Army of the Ethiopian Empire became the Army of the Federal Democratic Republic of Ethiopia .