Complex sentence: When the armistice was publicly declared, in the late afternoon of September 8, the majority of the Italian Army had not been informed about it and no orders had been issued about the line of conduct to be taken in the face of the German armed forces.
Split into simpler sentences: When the armistice was publicly declared, on September 8, the majority of the Italian Army had not been informed about it. No orders had been given at all about the line of conduct to be taken in the face of the German armed forces.