Craiova was bad enough, but almost worse was to follow; for on 23 November Mackensen succeeded in forcing the passage of the Danube beween Samovit and Sistovo, and by the 27th he effected a junction with Falkenhayn's armies which had swung east and were now across the Aluta advancing on Bukarest. The Rumanians' flanks were thus both turned by the crossing of the mountain passes and of the Danube, and they had no option but a rapid retreat to a line where those flanks held firm. That line did not cover the capital, and its elaborate forts would have been merely a trap for the Rumanian army. Nevertheless, a brave and skilful attempt was made to save it by a manoeuvre battle, and hopes were entertained in allied countries that Rumania was about to repeat the success of the Marne. The success could only come later when Averescu had flanks as secure as Joffre's. Still a wedge was for the moment driven between Mackensen and Falkenhayn's centre, and the movement might have succeeded had the reserves been up to time. Bukarest fell on the 5th, and for the rest of the year the Germans continued their progress eastwards until the Russo-Rumanian forces were able to stand on a line formed by the Danube, the Sereth, and the Putna ascending to the Oitos Pass. Sakharov had been forced to withdraw from the Dobrudja, and all that was left of Rumania was its Moldavian province, less than one-third of the kingdom, with its capital near the Russian frontier at Jassy. Sarrail's campaign in the south provided inadequate compensation. The part assigned to the British contingents under General Milne, which had taken over the front from the Vardar eastwards past Doiran and down the Struma to the sea, was the somewhat thankless one of pinning the Bulgars to that sector and preventing them from reinforcing the threatened line in the west. The various British attacks on villages east of the Struma, such as Nevolien, Jenikoi, Prosenik, and Barakli-Djuma, were thus merely raids, and the ground gained was soon evacuated for tactical or sanitary reasons. The serious offensive was towards Monastir, and the lion's part was played by the Serbian army with assistance from the French and a moderate Russian contingent; Italians from Avlona also fought occasionally. The Bulgarian offensive from Monastir in August had penetrated far into Greek territory, patrols even reaching Kailar, and it threatened, indeed, to turn Sarrail's left wing by an advance to the shores of the Gulf of Salonika when Sarrail began his attack on 7 September. The first serious fighting took place to the west of Lake Ostrovo, where on the 14th the Serbians captured Ekshisu. On the 20th they stormed Mount Kaymakchalan and recovered a footing on Serbian territory, while the French and Russians drove the Bulgars out of Florina. On the 29th, after furious Bulgarian counter-attacks, the Serbian general Mishitch descended the mountains towards the bend of the Tcherna river, and