Unification of Montenegro and Serbia is the one of the most interesting and most important issues of contemporary Montenegrin history. The entire contemporary history evolved in the shadows of this problem. Despite the existence of various political parties, the main political division in Montenegro between the two wars, end to the extent nowadays, is whites (bjelasi) and greens (zelenasi) (D.Vujovic, Crnogorski federalisti 1919-1929, CANU, 1981, Titograd, p.11). The manifestations associated with these two ideologies are, on one hand, manifestation of nationalism, localism, and chauvinism, (zelenasi), and on the other hand the phenomenon of national nihilism (bjelasi)(D.Vujovic, Ujedinjenje Crne Gore i Srbije, Istorijski institut NRCG, 1962, p. 8). It may be agued however, that this definition threat the greens or neo-greens somewhat harshly (See letters 1 and 2).

During the WW1 the unification of Montenegro and Serbia was the primary task of supporters of Greater Serbia project, led by Serbian Prime Minister Nikola Pasic. Pasic's aim was to just annex Montenegro without much public discussion and eventual negotiations. For that reason the Serbian government, and Pasic personally, formed the 'movement for unification' and embarked on a campaign (1916 and 1917), that was to show necessity and inevitability of unification. This became the official Serbian strategic policy approved by the Serbian government and Regent Alexander (D.Vujovic, Crnogorski federalisti 1919-1929, CANU, 1981, Titograd, p.13). 

Although 'movement for unification 'was under the Pasic's influence, following the Montenegrins' long lasted wish for the integration of South Slavs, it proposed that, "...Montenegro unifies with Serbia and other Yugoslav states". However, in order to insure his objective of Greater Serbia, Pasic was so meticulous, that he reformulated the proposal, dismissing any use of the word Yugoslavia or Yugoslavs (D.Vujovic, Crnogorski federalisti 1919-1929, CANU, 1981, Titograd, p.13). 

The preparations for a formal unification (Podgorica's Assembly) were very short. The supporters of unification chose most of the delegates for Podgorica Assembly (Podgoricka Skupstina) on their own meetings, but where meeting were not held, the delegates were simply named and invited by the organizer of the Podgorica's Assembly (D.Vujovic, Crnogorski federalisti 1919-1929, CANU, 1981, Titograd, p.14). 

Podgorica's Assembly took place in the Tobacco monopoly building on 11.11.1918. Some delegates demanded that, instead of rushing to unite, Montenegro was restored as sovereign country and than to negotiate the question of unity with the Serbian government. In order to prevent discussion "which would not lead to anything good and useful for the main thing which must be done urgently", the presidency of the Assembly assured that one detachment of army encircled the Assembly building and make pressure on hesitant delegates (J.Jovanovic, Stvaranje Crnogorske drzave i Razvoj Crnogorske nacije, 1948, Cetinje, p.436). 

Podgorica's Assembly, on its session of 13.11.1918, "unanimously" and "by acclamation" decided the following: 

• that King Nicholas I and his dynasty be dethroned for ever from Montenegrin throne; 
• that Montenegro unconditionally unite with Serbia in one state under dynasty of Karadjordjevic and so united "enter in mutual homeland our three-named people Serbs, Croats and Slovenes",
• and that these Assembly's decisions to be told to: ex King Nicholas I and his sons, Serbian and allied governments, as well as all neutral states (translated from J.Jovanovic, Stvaranje Crnogorske drzave i Razvoj Crnogorske nacije, 1947, Cetinje, p.436). 

Being so dismayed and disillusioned with Serbian Government and Serbian forces, many thousands of Montenegrins, took up arms (on Christmas eve of 1919) and surrounded towns of Cetinje, Niksic, Rijeka Crnojevica, and Virpazar. They demanded that Serbian troops left Montenegro, and that those who instrumentalized Podgorica's Assembly be tried. They, however, wanted to avoid bloodshed and issued the statement to Serbian authorities: 

"The assembly that took place in Podgorica on 11.11.1918, was scheduled in defiance of our Constitution, and above all, against the will of absolute majority of Montenegrins; therefore that led to uprising of Montenegrins against the decision of the Assembly whose executive branch is You...." (D.Vujovic, Crnogorski federalisti 1919-1929, CANU, 1981, Titograd, p.14). 

In 1920, Regent Alexander abolished the Montenegrin Autocephalous Orthodox Church by a decree. Also in an uncanonical and illegal manner property of Montenegrin Autocephalous Orthodox Church (~650) was transferred to the Serbian Orthodox Church and has not been reclaimed since.

Thus, ironically, Montenegro became the only Allied country in World War I to be annexed to another country after the end of the war even though it finished the war on the winning side. Moreover, following unification, Montenegro lost its official name and was administratively declared a region of Yugoslavia called Zeta (Zetska Banovina). 

Of all the constituent parts of this newly unified state, Montenegro had suffered conspicuously the greatest proportionate loss of life during World War I.

Links for: 
Serbo Rastoder: "Skrivena strana istorije - Crnogorska buna i odmetnicki pokret" (prikaz)
Historical Documents I - State Department Files....
Historical Documents II - State Department Files....
Historical Documents III - Serb insistence on Montenegrin surrender....
Historical Documents IV - The Paris Peace Conference....