Hypothesis Z ( ro, Ipoteza Z), sometimes known as Plan Z ( ro, Planul Z, link=no), was the name of

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, and ...

's first

war plan A military operation plan (also called a war plan before World War II) is a formal plan for military armed forces, their military organizations and units to conduct operations, as drawn up by commanders within the combat operations process in ac ...

for

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. It was based on an offensive against

Austria-Hungary Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...

Transylvania Transylvania ( ro, Ardeal or ; hu, Erdély; german: Siebenbürgen) is a historical and cultural region in Central Europe, encompassing central Romania. To the east and south its natural border is the Carpathian Mountains, and to the west the Ap ...

and a simultaneous defense of the country against Bulgarian attacks in the south. Once

Russian Russian(s) refers to anything related to Russia, including: *Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *Rossiyane (), Russian language term for all citizens and peo ...

forces had arrived in

Dobruja Dobruja or Dobrudja (; bg, Добруджа, Dobrudzha or ''Dobrudža''; ro, Dobrogea, or ; tr, Dobruca) is a historical region in the Balkans that has been divided since the 19th century between the territories of Bulgaria and Romania. I ...

, the

Romanian Army The Romanian Land Forces ( ro, Forțele Terestre Române) is the army of Romania, and the main component of the Romanian Armed Forces. In recent years, full professionalisation and a major equipment overhaul have transformed the nature of the Lan ...

would launch another offensive against Bulgaria. Hypothesis Z was definitively developed and completed by July 1916. Its application in the war in which Romania entered in August 1916 was unsuccessful, but its main objective, to achieve the unification of the

Romanian Romanian may refer to: *anything of, from, or related to the country and nation of Romania **Romanians, an ethnic group **Romanian language, a Romance language *** Romanian dialects, variants of the Romanian language ** Romanian cuisine, tradition ...

nation, was realised anyway after the war.

History

When

began, the

Chief of the Romanian General Staff The Chief of General Staff ( ro, Șeful Statului Major General) is the highest professional military authority in the Romanian Armed Forces. He is appointed by the President of Romania, at the National Defense Minister's proposal (with the appro ...

began studying and elaborating several

s with the objective of attending state interests in the new political and military scenario of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. The war plans were called "operation plans" or "hypotheses" and had several variants with the intention of adapting to any possible military situation. The plans were developed with the idea that a war against

could exist in three directions: south, northwest and east. Operations related to the south of the country (against

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...

) were assigned the letter A (Hypothesis A), those related to the northwest (against

) had the letter B (Hypothesis B) and those related to the eastern border (the one with

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

) had the letter C (Hypothesis C). The plans had many subvariants, which were differentiated through numbers (i.e., Hypothesis A1, Hypothesis A2, etc.). Between 1914 and 1916, subvariants of the hypotheses were prepared and studied. They initially treated a possible war with Russia but eventually switched mainly to a potential invasion of Austro-Hungarian territory and the defence of the border with Bulgaria. This plan came to be known as Hypothesis B3. Between March and April 1916, the last studies of the subvariant were performed, and it was agreed that it would be used in the case of war. Thus, it was determined that Romania would launch an offensive against Austria-Hungary and defend itself from Bulgaria, with Hypothesis B3 earning the name of "Hypothesis Z". Romania was supposed to defend itself from Bulgarian attacks until the arrival of Russian troops in

, and only then, it would begin an offensive into Bulgarian territory. The Chief of the Romanian General Staff finalised the Romanian war plan in July 1916 and began distributing it to Romanian commanders. Hypothesis Z had Romania intend to conquer all territories from Austria-Hungary populated by

Romanians The Romanians ( ro, români, ; dated exonym '' Vlachs'') are a Romance-speaking ethnic group. Sharing a common Romanian culture and ancestry, and speaking the Romanian language, they live primarily in Romania and Moldova. The 2011 Roman ...

and the unification of the Romanian nation. Hypothesis Z started its application after the entrance of Romania into World War I in August 1916. According to it, the , the First Army and the Second Army (about 75% of the

) were to begin an offensive in Transylvania towards

Brașov Brașov (, , ; german: Kronstadt; hu, Brassó; la, Corona; Transylvanian Saxon: ''Kruhnen'') is a city in Transylvania, Romania and the administrative centre of Brașov County. According to the latest Romanian census (2011), Brașov has a pop ...

Târgu Mureș Târgu Mureș (, ; hu, Marosvásárhely ) is the seat of Mureș County in the historical region of Transylvania, Romania. It is the 16th largest Romanian city, with 134,290 inhabitants as of the 2011 census. It lies on the Mureș River, the ...

, Cluj-Napoca and finally

Budapest Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population ...

. On the other hand, the Third Army (the remaining 25%) would stay on the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , p ...

and in Dobruja to defend Romania from Bulgarian attacks. The , constituting the

army reserve A military reserve force is a military organization whose members have military and civilian occupations. They are not normally kept under arms, and their main role is to be available when their military requires additional manpower. Reserve ...

, would initially be placed near

Bucharest Bucharest ( , ; ro, București ) is the capital and largest city of Romania, as well as its cultural, industrial, and financial centre. It is located in the southeast of the country, on the banks of the Dâmbovița River, less than north of ...

and then move to Transylvania. The

Romanian Danube Flotilla The Romanian Danube Flotilla is the oldest extant naval force on the Danube, dating since 1860, when the Romanian Navy was founded. It saw service during most of the wars involving Romania, and was the most powerful river naval force in the world du ...

was placed near the Dobrujan port of Turtucaia. The total number of soldiers to participate was 562,847, 420,324 for the Transylvanian front and 142,523 for the Bulgarian front. In the end, even though the Romanian Army faced initial defeats during the war, the aim of Hypothesis Z, the national unification of the Romanians, was achieved on its aftermath by the

Great Union In Romanian historiography, the Great Union ( ro, Marea Unire) or Great Union of 1918 () was the series of political unifications the Kingdom of Romania had with several of the so-called Romanian historical regions, starting with Bessarabia on ...

References

{{Great Union 1916 in Romania 1916 in military history Military history of Romania Military plans Romania in World War I Great Union (Romania) Invasions by Romania Romanian Land Forces

History

See also

References