[3] Gratitude for his imperial education is said to have led him to refuse an invitation from fellow Venetians to change sides in the Third War of Independence of 1866, in which he won the Order of Maria Theresa for his services as a captain on the Bohemian front.

He occupied Asmara and other Eritrean territories, wresting control from the armies of Ras Alula, and had planned further Italian colonial expansion by taking advantage of the chaotic internal divisions of the Ethiopian Empire of the day.

When the First Italo-Ethiopian War broke out in 1895 the then Governor of Eritrea, General Oreste Baratieri, did not enjoy the confidence of the Italian government, which decided to replace him with Baldissera.

Although the appointment was kept secret, Baratieri got wind of it, likely persuading him to attack the Ethiopian army, despite having inferior military forces and insufficient supplies, in an apparent attempt to win glory for himself before his successor's arrival.

He was able to repel King Menelek II's forces and retake a significant portion of the lost territory, liberating Italian troops who had been left stranded in Adigrat and Kassala.

[1] Following Italy's recognition of Ethiopia as an independent country in the Treaty of Addis Ababa, he was forced to restrict his activities to a partial internal reorganization of Eritrea, curtailed by an unsupportive Italian government that had tired of colonial affairs.