Second Battle of Tembien  The Second Battle of Tembien was a battle fought on the northern front of what was known as the Second Italo-Abyssinian War. This battle consisted of attacks by Italian forces under Marshal Pietro Badoglio on Ethiopian forces under "Ras" Kassa Haile Darge and "Ras" Seyoum Mangasha. This battle, which resulted in a decisive defeat of Ethiopian forces, was primarily fought in the area around the Tembien Province. The battle is notable for the large-scale use of mustard gas by the Italians. On 3 October 1935, General Emilio De Bono advanced into Ethiopia from Eritrea without a declaration of War. De Bono advanced towards Addis Ababa with a force of approximately 100,000 Italian soldiers and 25,000 Eritreans. In December, after a brief period of inactivity and minor setbacks for the Italians, De Bono was replaced by Badoglio. Ethiopian Emperor Haile Selassie launched the Christmas Offensive late in the year to test Badoglio. Initially successful, the goals of this offensive were overly ambitious. As the progress of the Christmas Offensive slowed, Italian plans to renew the advance on the northern front got under way. In addition to being granted permission to use poison gas, Badoglio received additional ground forces. The elements of the Italian III Corps and the Italian IV Corps arrived in Eritrea during early 1936. By mid-January 1936, Badoglio was ready to renew the Italian advance. In response to his frequent exhortations, Badoglio cabled Mussolini: "It has always been my rule to be meticulous in preparation so that I may be swift in action." In early January 1936 Ethiopian forces were in the hills overlooking the Italian positions and launching attacks against them on a regular basis. The Ethiopians facing the Italians were in three groups. In the center, near Abbi Addi and along the Beles River in the Tembien, were "Ras" Kassa with approximately 40,000 men and "Ras" Seyoum with about 30,000 men. On the Ethiopian right was "Ras" Mulugeta Yeggazu and his army of approximately 80,000 men in positions atop Amba Aradam. "Ras" Imru Haile Selassie with approximately 40,000 men was on the Ethiopian left in the area around Seleclaca in Shire Province. Only a minority of the Ethiopian soldiers had received military training, there were few modern weapons and less than one rifle per man.