Rumania's gamble

Roumania 1916, unlike today's familiar 
rectangular shape. The large and disputed region
of Transylvania formed a prominent 
mountainous  salient.

Roumania had spent the war to date sitting on the fence of neutrality. Created as a sovereign nation out of the Treaty of Berlin in 1878, her independence from the Ottoman Empire was still new and tense; her population a mix of religions and ethnicities alongside a Roumanian majority. Bulgaria to the south was fighting with the central powers, and her other borders were with predatory empires – Austria Hungary to the west and north-west, and Russia to the north east. The former was in the form of the disputed Hungarian province of Transylvania with its 3 million ethnic Roumanians. The river Danube marked the southern border to the huge delta entering the Black Sea, with the exception of the Dubroja, a bleak province of land to the south of the delta, of historic importance for its routes to Constantinople and the Caucasus. At the northern border the eastern end of the Carpathian mountain range crossed from north to south west, and then turned sharply west to form the Transylvanian alps – one continuous range of mountain that made Roumania’s western border a prominent salient, not unlike the Adige salient bulging into Italy .

Rich in oil and agricultural resources, Roumania was coveted by both sides in the great struggle. Until 1916 she had managed to maintain what Churchill describes as "ambiguous watchfulness”. In fact, at the beginning of 1916 it looked more likely that she would side with the central powers - like her hostile neighbour, Bulgaria. By mid 1916 the situation had changed. With Falkenhayn’s strategic decision to attack Verdun, and Austria’s assault on Italy, the eastern front was weakened, enabling Brusilov’s offensive to capitalize, and the perceived pressure on Roumania melted away. (See Blogs Verdun 5/2/16; Austria 3/5/16 and Brusilov 15/5/16) 

As news of Brusilov’s rapid advances became known, the pro-French Roumanian King Ferdinand took the opportunist gamble to declare war and seize a vulnerable Transylvania. However, he wasted the opportunity for surprise by protracted covert negotiations with the Allies for their support. He wanted pressure on the Bulgarians to limit their ability to threaten his southern border which, although mostly protected by the width of the Danube, was vulnerable at its eastern end via the Dubroja. He also desperately needed Russian strength to cover the northern aspects of any campaign. Both were agreed in principle but the discussions were complex and the allied commitment was half hearted. Britain and France would have preferred a Roumanian strike south into Bulgaria to help with their attempts to cut the main communications from Vienna to Constantinople. The Russians were willing enough to provide support, but their railway lines ran out a long way short of the border with Roumania’s northern province of Moldavia, and it would take time to build up strength. Eventually, Ferdinand’s bargaining resulted in a undertaking for Sarrail’s Salonika forces to strike north into Bulgaria. This was a massively ambitious undertaking into hostile mountainous country along a single railway line against the fiercely defensive southern Bulgarian forces. In the event Sarrail was able to make little progress, and did not influence actions on Roumania’s southern border. The Russian contribution meant that they had to extend Brusilov’s predominantly south western movement towards the east, thereby testing his already stretching communication lines. Even worse, the two months of delay enabled the Germans to adjust to the pressures on the Western Front, and shore up the damage to the Eastern Front caused by Austria’s collapse against Brusilov.

Ferdinand I, King of Roumania 1914-27.
Francophile, despite his Hohenzollern
blood line

Had Ferdinand struck in July when the Somme battle was raging at its fiercest, Germany would not had had time, or the resources, to switch forces to the east. In fact, it was 27^th August before Ferdinand declared and invaded Transylvania, by which time they had blunted Brusilov’s progress and were strengthening the Austrian forces nearer to Roumania. Nevertheless, Roumania’s abrupt actions came as a shock to the German and Austrian public, and were sufficient to seal Falkenhayn’s fate as military supremo. Paying the price for failure at Verdun (and to a lesser extent scapegoat for the Brusilov and Somme offensives) he was replaced by the Eastern Front hero partnership of Hindenburg and Ludendorff. With some irony, this great champion of strategic action on the Western Front was consigned to command of the easternmost section of the Eastern Front – the very army about to do battle with the Roumanian forces invading Transylvania.

King Ferdinand had around half a million men at his disposal, and added reserve forces as rapidly as he could. They were brave and determined fighters, but officers and men were inexperienced and poorly armed. In technology and communications they were way behind other combatants, and with hindsight it is easy to see how their foray into enemy country backfired, turning into a deadly trap of a German pincer movement.

The disposition of Ferdinand's armies, and the
jaws of the German pincer movements.
(Adapted from Churchill. The Great War p931)

Ferdinand organised his forces into four armies; the 3rd was to cover the Dobruja border with Bulgaria in the south, with some Divisions guarding the Danube crossings further west; and the 1st 2^nd, and 4^th were assigned the key passes of the Transylvanian salient (see map). For the first few days the planned invasion went well, and news of Roumanian success was received excitedly in Bucharest and the Allied capitals. In a fortnight from 27^th August the invaders penetrated fifty miles holding the numerous mountain passes, frontier towns and the main regional railhead. But this was Roumania’s high point, and from here matters unraveled rapidly. The first major blow came from the south. In charge of the German counterstroke that surged into Dubroja was August von Mackensen (see Blog 3/7/15), the brilliant veteran general whose exploits in Russia and the Balkans we have already seen. He was in the Balkans still, and was given command of a German led force that also included Bulgarian and Turkish divisions. With his customary zeal and ruthlessness, he transported his heavy artillery to the Danube; demolished the key fortified crossing point of Turturkai (capturing 25,000 Roumanians) and burst into Dobruja, outflanking the bulk of the 3rd army. Leaving some of his forces to deal with them, and also to supervise transfer of more supplies across the Danube, he pushed on and by the end of September was at Constanza, the main port on the Black Sea.

From the north, Falkenhayn was now pushing back at the 1st and 2^nd armies’ bridgehead, and also at the 4^th, which had descended west from the Carpathians. In the face of superior forces, the Roumanian resistance was strong and plucky, but the invasion of Dobruja was a crisis that rapidly used up all Ferdinand’s scanty reserves. Angry disagreement ensued between his generals – those in the south demanding withdrawal of troops from the north and west; and those in the north refusing to withdraw from ground they had won. Ferdinand’s inevitable compromise ruling benefited nobody except the Germans, and the jaws of their pincer began to close. Although slowed by resolute defenders, Mackensen broadened his front and threatened Bucharest from south and east. Falkenhayn and some Austrian led forces penetrated the mountain passes and pushed the Romanians back from north and west. They advanced rapidly between the Carpathians and the river Sereth (an enormous northern tributary of the Danube) to threaten encirclement of Bucharest.

On November 26^th Mackensen and Falkenhayn linked up to the west of Bucharest, and on 6^th December, after fierce fighting they entered the city (Mackensen on a white steed). The remnants of the army and government fought a rearguard action north eastwards, pursued by the Germans in dreadful weather and conditions. With the belated arrival of Russian support to the north, Ferdinand was able to establish a garrison at Jassy close to the Russian border and hold on to their northernmost province of Moldavia.

Another Balkan nation had been eviscerated by the German machine. Despite brave resistance, it was men v boys militarily. Although the Roumanians, under British guidance, were able to scupper most of their oil wells in retreat, the victory won essential resources of oil and grain that helped the Austrian and German populations, and prolonged the war, now into its third agonising winter.