On 1 December 1916, in World War I, the Romanian army under General Constantin Prezan struck the flank of August von Mackensen's Danube Army on the Neajlov River, southwest of Bucharest. The attack gained ground at first, but the Germans captured the Romanian orders, and by 3 December it had collapsed. Bucharest fell on 6 December.1
Two armies closing on the capital
Romania entered the war on the Allied side in August 1916 and opened with an offensive into Transylvania. The Central Powers struck back. Erich von Falkenhayn's Ninth Army drove the Romanians out of Transylvania and in November broke through the Carpathians into Wallachia, while Mackensen's forces, which had overrun Dobruja, crossed the Danube. The historian Sorin Cristescu, speaking to Radio Romania International, places the crossing at Zimnicea, at about the time Falkenhayn's troops crossed the Olt, around 23 November. By the end of November the two enemy armies were converging on Bucharest.2
Romania still kept the Julian calendar, so Romanian accounts give the battle that followed old and new style dates, from 16/29 November to 20 November/3 December 1916. Romanian writers call it the Battle of Bucharest or the Battle of the Neajlov and Argeș.3
Prezan's gamble
General Constantin Prezan commanded the operation. His idea, as Cristescu describes it, was to strike the two German armies one at a time before they could join, while waiting for Russian reinforcements that came late. The historian George Marcu, quoted by Adevărul, writes that Romanian appeals for Russian troops brought no real result. Falkenhayn later summed up the Romanian plan in a note quoted by the Romanian magazine Historia: the 1st Army, about four divisions, would hold the line of the Argeș, while a maneuver group of four infantry divisions and a cavalry division fell on the left flank of Mackensen's Danube Army and two Russian divisions pinned its right wing. The plan, he wrote, would not have been a bad one had it not ignored the German group under Kühne coming up from the west.4
The blow fell across the Neajlov. According to Marcu, on 1 December the Romanians won successes in every sector and threw the enemy back with heavy losses. Historia agrees that the first attacks succeeded before the Romanian units were overwhelmed by German numbers and guns.5
The captured orders
Then the plan was lost. A Romanian army car carrying operation orders fell into German hands. In Falkenhayn's note, the order was beyond doubt genuine, taken from two Romanian staff officers who had strayed with their car into the German lines, and it “completely dispelled the darkness” about Romanian intentions. The Germans now knew where the Romanian units stood and what they meant to do. Cristescu, for his part, argues that German superiority would have decided the battle even without the lost car.6
On 3 December the Germans struck the Romanian forces between the Neajlov and the Argeș from several sides at once, Falkenhayn's divisions falling without warning on their rear. By the morning of 4 December, Marcu writes, the whole line of the Argeș was in enemy hands; Cristescu agrees that by then Bucharest could not be defended.7
The fall of Bucharest
The Romanian command decided to give up the capital without a fight. German, Austro-Hungarian and allied troops occupied Bucharest on 6 December 1916. The court and the government had already moved north to Iași, in Moldavia.8
The rest of the Romanian army fell back into Moldavia, where, with Russian troops at last beside it, it built a new line and stopped the Central Powers. The occupation of Bucharest lasted until November 1918.9
