During the spring of 1916 the Germans and Bulgars had been busy preparing for an offensive on a large scale against the Allies. The 11th Bulgarian Division, composed of Macedonian troops, who were not too trustworthy and provided a number of deserters, was dissolved. The Monastir front was strengthened with units drawn from the Dobrugia and Eastern Macedonia. In the spring there were 3 Bulgarian divisions between Strumitza and Xanthi, 3 in the Dobrugia and 5 in the Monastir area, in addition to 2 German divisions, and in July we have the following distribution of forces; 3 divisions and 1 cavalry brigade in the Dobrugia, 2 brigades and some other units on the Struma, 2 Bulgarian and 1 German division (the only one left in Macedonia) on the Vardar, all these forces being detailed for the attack on the entrenched camp at Salonica. In the Monastir plain there was a mobile reserve for attack consisting of two infantry divisions and 3 cavalry brigades. In all, 8 Bulgarian infantry and 1 cavalry division, 1 German division, and 1 or 2 Turkish divisions. The plan consists of a rapid offensive on the two wings, with the object of cutting the Allies’ retreat towards Greece or Albania,[12] so as to oblige General Sarrail to fight a siege battle and perhaps to capitulate. Since the retreat along the Vardar down to the summer of 1916 Sarrail had had orders to remain on the defensive, but now that the alliance with Roumania had been concluded, the Entente Powers contemplated, as we have seen, an operation in Macedonia to give support to the Roumanian Army and perhaps effect a junction with it. Roumania declared war on August 28th, but she had asked that the Army of the Orient should attack ten days before. It was, on the contrary, the enemy who was the first to attack. General Sarrail was now “Commander-in-Chief of the Allied Armies in the Orient,” and his command was known as the _Commandement des Armées Alliées_, abbreviated “C.A.A.” The French troops under his orders were grouped together under the name of _Armée française d’Orient_ (commonly called the “A.F.O.”), and then commanded by General Cordonnier. It was the latter who conducted the operations of the summer and autumn of 1916. On August 17th the Bulgarians crossed the Greek frontier at two points, advancing eastward to the mouth of the Struma and westward towards Lake Ostrovo, which they reached on the 23rd. Soon after they occupied Florina and Banitza, obliging the Serbs, who were holding that area, to fall back on Ekshisu and Sorovich.