The division of the Roman Empire between Roman and Byzantine rule – and subsequently between the Latin and Greek churches – was marked by a line that ran northward from Skadar through modern Montenegro, symbolizing the status of this region as a perpetual marginal zone between the economic, cultural, and political worlds of the Mediterranean peoples and the Slavs. As Roman power declined, this part of the Dalmatian coast suffered from intermittent ravages by various semi-nomadic invaders, especially the Goths in the late fifth century and the Avars during the sixth century. These soon were supplanted by the Slavs, who became widely established in Dalmatia by the middle of the seventh century. Because the terrain was extremely rugged and lacked any major sources of wealth such as mineral riches, the area that is now Montenegro became a haven for residual groups of earlier settlers, including some tribes who had escaped Romanisation.
In the first half of the seventh century, Serbs migrated from the Bay of Kotor to the River of Bojana, an area of land given to them by the Byzantine Emperor Heraclius. They formed the Principality of Doclea. Under the following missions of Cyril and Methodus, the population was Christianised. The Serbian tribes organised into a semi-independent dukedom of Duklja(Doclea) by the tenth century. After facing subsequent Bulgarian domination, the people were split as the Doclean brother-archonts split the lands among each other after 900. Prince Časlav Klonimirović of the Serbian House of Vlastimirović extended his influence over Doclea in the tenth century. After the fall of the Serbian Realm in 960, the Docleans faced a renewed Byzantine occupation through to the eleventh century. The local ruler, Jovan Vladimir, whose cult still remains in the Orthodox Christian tradition, was at the time struggling to ensure independence.
Stefan Vojislav started an uprising against the Byzantine domination and gained a huge victory against the army of several Byzantine strategs in Tudjemili (Bar) in 1042, which put to an end the Byzantine influence over the Doclea.In the 1054 Great Schism, the Doclea fell on the side of the Catholic Church. Bar became a Bishopric in 1067. In 1077, Pope Gregory VII recognised Duklja as an independent state, acknowledging its King Mihailo (Michael, of the House of Vojisavljević founded by nobleman Stefan Vojislav) as rex Doclea (King of Duklja). Later on Mihailo sent his troops, led by his son Bodin, in 1072 to assist the uprising of Slavs in Macedonia. In 1082, after numerous pleas the Bar Bishopric of Bar was upgraded to an Archbishopric.
The expansions of the Kings of the House of Vojislavljević led to the control over all Serbian lands, including Zahumlje, Bosnia and Rascia. The might of the Doclea declined and they generally became subjected to the Grand Princes of Rascia in the 12th century. Stefan Nemanja was born in 1117 in Ribnica (today Podgorica). In 1168, as the Serbian Grand Zhupan, Stefan Nemanja took Doclea.
After the fall of the Western Roman Empire (476), the romanised Illyrians of the coast of Dalmatia survived the barbarian invasions of the Avars in the sixth century and were only nominally under the influence of the Slavs in the seventh and eighth centuries. In the last centuries of the first millennium, these Romanised Illyrians started to develop their own neo-Latin language, called Dalmatian language, around their small coastal villages that were growing with maritime commerce.
Venice started to take control of the southern Dalmatia around the tenth century, assimilating quickly the Dalmatian language into the Venetian language. But only in the fourteenth century the Republic of Venice was able to create a territorial continuity around the Bay of Kotor (Cattaro).
The Republic of Venice dominated the coasts of today's Montenegro from 1420 to 1797. In those four centuries the area around the Cattaro (Kotor) became part of the Venetian albania-montenegro, called in those centuries Albania veneta.
When the Turks started to conquer the Balkans in the fifteenth century, many Christian Slavs took refuge inside the venetian Dalmatia. By the end of the seventeenth century the romance speaking population was already a minority. But still in 1880 there were in the city of Cattaro, according to the Austrian census, 930 ethnic Italians (or 32% of a total population of 2910 people).
In 1516, the secular prince Đurađ V Crnojević abdicated in favor of the Archbishop Vavil, who then formed Montenegro into a theocratic state under the rule of the prince-bishop (vladika) of Cetinje, a position transmitted from 1697 by the Petrović-Njegoš family of the Riđani clan, from uncle to nephew as the bishops were not allowed to marry. Petar Petrović Njegoš perhaps the most influential vladika, reigned in the first half of the nineteenth century. In 1851 Danilo Petrović Njegoš became vladika, but in 1852 he married, threw off his ecclesiastical character, assuming the title of knjaz (Prince) Danilo I, and transformed his land into a secular principality.
Following the assassination of Danilo by Todor Kadic, in 1860, the Montenegrins proclaimed Nicholas I as his successor on August 14 of that year. In 1861 – 1862, Nicholas engaged in an unsuccessful war against Turkey, Montenegro holding onto its independence only by the skin of its teeth.
He was much more successful in 1875. Following the Herzegovinian Uprising, partly initiated by his clandestine activities, he yet again declared war on Turkey. Serbia joined Montenegro, but it was defeated by Turkish forces in 1876 only to try again the following year after Russia decisively routed the Turks. Montenegro was victorious throughout, though. The results were decisive; 1,900 square miles were added to Montenegro's territory by the Treaty of Berlin; that the port of Bar and all the waters of Montenegro were closed to the ships of war of all nations; and that the administration of the maritime and sanitary police on the coast was placed in the hands of Austria.
The reign of Nikola I (1860 – 1918) saw the doubling of Montenegro's territory and international recognition of her independence (1878).
He also granted the country's first constitution (1905) and was elevated to the rank of King (1910).
In addition, the newly-captured city of Skadar had to be given up to the new state of Albania at the insistence of the Great Powers despite the Montenegrins having invested 10,000 lives for the conquest of the town from the Ottoman-Albanian forces of Esad Pasha.
Montenegro suffered severely in World War I. At the first invasion of Serbia by the Austro-Hungarian armies, Montenegro lost no time in declaring war against the Central Powers. Austria-Hungary despatched a separate army to invade Montenegro and to prevent a junction of the Serbian and Montenegrin armies. This force, however, was repulsed, and from the top of the strongly fortified Mount Lovćen, the Montenegrins carried on the bombardment of Kotor held by the enemy. On August 10, 1914, the Montenegrin infantry delivered a strong attack against the Austrian garrisons, but they did not succeed in making good the advantage they first gained. They successfully resisted the Austrians in the second invasion of Serbia and almost succeeded in liberating Sarajevo. With the beginning of the third Austro-Hungarian invasion, however, the Montenegrin army had to retire before greatly superior numbers, and Austro-Hungarian and German armies finally overran Serbia. Montenegro also suffered invasion (January 1916) and for the remainder of the war remained in the possession of the Central Powers. See Serbian Campaign (World War I) for details. Military governor of Montenegro between 1916 and 1917 was Viktor Weber Edler von Webenau. Afterwards Heinrich Clam-Martinic filled this position.
King Nicholas fled to Italy and then to France; the government transferred its operations to Bordeaux. Eventually the allies liberated Montenegro from the Austrians. A newly-convened National Assembly of Podgorica (Podgorička skupština, Подгоричка скупштина), accused the Кing of seeking a separate peace with the enemy and because of that deposed him, followed by a ban on his return and decided that Montenegro should join the Kingdom of Serbia on December 1, 1918. Part of Montenegrin population started a rebellion,which is known as Christmas uprise.
During WWII Mussolini occupied Montenegro in 1941 and annexed to the Kingdom of Italy the area of Kotor (Cattaro), where there was a small Venetian speaking population (the Queen of Italy - Elena of Montenegro - was daughter of the former king of Montenegro and was born in Cetinje). The English historian Denis Mack Smith wrote that the Queen of Italy (considered the most influential Montenegrin woman in history) convinced her husband the King of Italy Victor Emmanuel III to impose on Mussolini the creation of an independent Montenegro, against the wishes of the fascists Croats and Albanians (who wanted to enlarge their countries with the Montenegrin territories). Her nephew Prince Michael of Montenegro never accepted the offered crown, pledging loyalty to his nephew King Peter II of Yugoslavia.
The puppet Independent State of Montenegro was created under fascist control when Krsto Zrnov Popović returned from his exile in Rome in 1941 to attempt to lead the Zelenaši ("Green" party), who supported the reinstatement of the Montenegrin monarchy. This militia was called the Lovćen Brigade. Montenegro was ravaged by a terrible guerrilla war, mainly after Nazi Germany replaced the defeated Italians in September 1943.
From 1945 to 1992, Montenegro became a constituent republic of the Socialist Federal Republic of Yugoslavia. Montenegro became economically stronger than ever, since it gained help from federal funds as an under-developed Republic, and it became a tourist destination as well.
In effect three men ran the republic: Milo Đukanović, Momir Bulatović and Svetozar Marović; all swept into power during the so-called "anti-bureaucratic revolution"—an administrative coup of sorts within the Yugoslav Communist party, orchestrated by younger party members close to Slobodan Milošević.
All three appeared devout communists on the surface, but they also had sufficient skills and adaptability to understand the dangers of clinging to traditional rigid old-guard tactics in new and changing times. So when the old Yugoslavia effectively ceased to exist and the multi-party political system replaced it, they quickly repackaged the Montenegrin branch of the old Communist party and renamed it the Democratic Party of Socialists of Montenegro (DPS).
Inheriting the entire infrastructure, resources and membership of the old Communist party gave the DPS a sizable head start on their opponents in the newly-formed parties. It allowed them to win parliamentary and presidential elections overwhelmingly. The party has ruled Montenegro ever since (either alone or as a leading member of different ruling coalitions), never losing power for even a day.
During the early to mid 1990s Montenegro's leadership gave considerable support to Milošević's war-effort. Montenegrin reservists fought on the Dubrovnik front line, where Prime Minister Milo Đukanović visited them frequently.
In May, the United Nations imposed an embargo on FRY: this affected many aspects of life in the country.
Due to its favourable geographical location (access to the Adriatic Sea and a water-link to Albania across Lake Skadar) Montenegro became a hub for smuggling activity. The entire Montenegrin industrial production had stopped, and the republic's main economic activity became the smuggling of user goods - especially those in short supply like petrol and cigarettes, both of which skyrocketed in price. It became a de facto legalized practice and it went on for years. At best, the Montenegrin government turned a blind eye to the illegal activity, but mostly it took an active part in it. Smuggling made millionaires out of all sorts of shady individuals, including senior government officials. Milo Đukanović continues to face actions in various Italian courts over his role in widespread smuggling during the 1990s and in providing safe haven in Montenegro for different Italian Mafia figures who also allegedly took part in the smuggling distribution chain.
In 1997 a bitter dispute over presidential election results took place. It ended with Milo Đukanović winning over Momir Bulatović in a second-round run-off plagued with irregularities. Nonetheless, the authorities allowed the results to stand. Former close allies had by this time become bitter foes, which resulted in a near-warlike atmosphere in Montenegro for months during the autumn of 1997. It also split the Democratic Party of Socialists of Montenegro. Bulatović and his followers broke away to form the Socialist People's Party of Montenegro (SNP), staying loyal to Milošević, whereas Đukanović began to distance himself from Serbia. This distance from the policies of Milošević played a role in sparing Montenegro from the heavy bombing that Serbia endured in the spring of 1999 during the NATO air-campaign.
Đukanović came out a clear winner from this political fight, as he never lost power for even a day. Bulatović, on the other hand, never held office again in Montenegro after 1997 and eventually retired from politics in 2001.
In 2003, after years of wrangling and outside assistance, the Federal Republic of Yugoslavia renamed itself as "Serbia and Montenegro" and officially reconstituted itself as a loose union. The State Union had a parliament and an army in common, and during the three years (till 2006), neither Serbia nor Montenegro held a referendum on the break-up of the union. However, a referendum was announced in Montenegro to decide the future of the republic. The ballots cast in the controversial Montenegrin independence referendum, 2006 resulted in a 55.5% victory for independence supporters, just above the 55% borderline mark set by the EU. Montenegro declared independence on June 3, 2006.