Fort Rupel, on the Struma River, and north of Demir Hissar, is about six miles within Greek territory. It commands a deep gorge, or defile, which forms a sort of natural passageway through which troops can be marched easily into Greek territory from Bulgaria. To either side tower difficult mountains and rocky hills. On account of these natural features Greece had fortified this defile after the Balkan Wars so that she might command it in case of a Bulgarian invasion. On the commanding prominences the Greeks had also built fortifications. It was the chief, the most important, of these forts that the Bulgarians took. A courier was sent forward with notice to the Greek commander that he had two hours in which to evacuate the position with his troops. This he did peacefully, and before evening the Bulgarians were installed, though it was said that they had given due assurances that their occupation was merely a temporary measure undertaken as a defensive precaution, and that as soon as the need should cease the fort would be returned to Greece. On the following day came the announcement that the Bulgarians, in strong force, had deployed from Fort Rupel and had also occupied Fort Dragotin and Fort Kanivo. At the same time unusual activity on the part of the Bulgarians was also reported from Xanthi. Here, on the left bank of the Mesta River, which for some distance from its mouth forms the Bulgar-Greek boundary, the Bulgarians were collecting material for building pontoon bridges. Naturally this action on the part of the Bulgarians caused wild excitement throughout Greece. The government organs stated that the forts had been taken by German forces, but this was soon proved to be untrue. In reporting this movement the Bulgarian Government added, by way of explanation and excuse: "Two months ago the Anglo-French troops began the abandonment of the fortified camp at Saloniki and started a movement toward our frontier. The principal enemy forces were stationed in the Vardar Valley and to the eastward through Dovatupete to the Struma Valley, and to the westward through the district of Subotsko and Vodena to Florina. A part of the reconstituted Serbian army has also been landed at Saloniki. Artillery fire has occurred daily during the past month." Evidently Bulgaria was anxious to impress on the outside world the fact that she had invaded Greek territory entirely for defensive purposes, for only several days later a correspondent of the Associated Press was allowed to send through a report of an inspection he had made of the Bulgarian camp, something that had not previously been permitted. From this report it was evident that the Bulgarian army was not contemplating a forward movement.