division was ordered to concentrate around Kratovo, where it would remain under the direct control of the Bulgarian high command. The cavalry division and the 8th "Tunzha" infantry division were also ordered to join the First Army. Macedonian Front With the successful conclusion of the Serbian campaign and withdrawal of the French and British expeditionary forces back to Salonika the Bulgarian armies reached the Greek border. Under the influence of the German high command they were ordered not to cross into Greek territory. The Bulgarian commander-in-chief general Nikola Zhekov remained concerned about the increasing Allied presence in Greece and insisted upon an attack on Salonika. Instead on 9 February 1916 during a meeting in the German military headquarters in Pleß he and the Chief of the General Staff von Falkenhayn agreed to begin fortifying the positions that were already taken on the Greek border and to resolve the question of an offensive latter. Since December 1915 the Bulgarian First Army consisted of the 8th, 9th and 3rd infantry divisions and the cavalry divisions and occupied a 140-kilometer front, from Debar and Struga to the bend of the river Cherna and the Vardar. It remained part of Army Group "Mackensen", which had its headquarters in Skopje, together with the Bulgarian 5th "Danube" division, the German 4th Reserve Corps and the German 210th composite brigade which formed the Eleventh Army. In the spring of 1916 as the Allies had finished fortifying the area around Salonica and it became obvious that no Bulgarian and German offensive was going to take place, the French and British forces moved up to the Greek border where they established contact with the Bulgarian forces. In the beginning of April the positions of the Eleventh Army were subjected to heavy artillery shelling and field marshal Mackensen requested the 9th "Pleven" infantry division to be given to that army so that it can consolidate its position. General Zhekov agreed and ordered the division to leave the First Army, join the Eleventh Army and concentrate behind the German 4th Corps. By 1 June the Entente forces were additionally strengthened by the arrival of some 115,488 Serbian soldiers, which were organized in three corps-sized formations called armies. The Allies now had over 313,000 troops in the theater which increased the Bulgarian concerns. By July Romania was preparing to enter the war on the side of the Entente which placed Bulgaria in