1,2: 1874/1898 Definitives: Prince Nikola I (1)
3: Printing in Montenegro (2) 400th Anniversary (1893)
4: Advice of Receipt (1895)
5: Ruling Dynasty (3) Bycentenary (1896)
6: 1902 Nikola I Definitives
7: 1902 Advice of Receipt
8: 1905 Granting of Constitution (4)
9: 1907 Nikola I Definitives
10: 1907 Advice of Receipt
11-22: Proclamation of Kingdom and Coronation of Nikola I (1910)
23: 1913 King Nikola I Definitives 1913
24: 1913 Advice of Receipt
25: 1894 Postage Due Stamps
26: 1907 Postage Due Stamps

(1) Nikola I Petrovic Njegos (1841-1921) was the only king of Montenegro, reigning as a king from 1910 to 1918 and as a prince from 1860 to 1910.
Nikola became sovereign prince of Montenegro on the assassination of his uncle Danilo II in 1860. The country was embroiled in a series of wars with the Ottoman Empire between 1862 and 1878. However, the independence of Montenegro was recognized by all other countries at the Congress of Berlin in 1878 and in the succeeding decades Montenegro enjoyed considerable prosperity and stability. Education, communications and the army expanded greatly. Nikola gave Montenegro its first constitution in 1905 following pressure from a population eager for more freedom. He also introduced west-European style press freedom and criminal law codes.
The Montenegrin parliament declared Nikola king in 1910. After the First World War Montenegro was forced to unite with the Kingdom of Serbia, as well as with other south Slav lands, to form the Kingdom of Serbs, Croats and Slovenes. A national uprising against coerced "union" was crushed thereafter.
Nikola went into exile in France 1918, but continued to claim the throne until his death three years later. He was buried in Italy. In 1989, his remains were re-buried in Montenegro.

(2) To help counter Roman Catholic and Islamic influence, a Montenegrin ruler, Ivan Crnojevic, obtained in 1494 a printing press from Venice, which was operated by a monk named Makarije. The first book printed on the Obod press by Makarije was the Orthodox service book, the Octoechos, which is the first printed Cyrillic book of the South Slavs. Thus, only 39 years after Gutenberg's Bible, Montenegro had its own press and Cyrillic books.

(3) In 1516, the secular prince Djuradj Crnojevic 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 held from 1697 by the Petrovic-Njegos family.

(4) On 19.12.1905 Prince Nikola I decreed the end of autocratic government, established a parliamentary government and granted a liberal constitution. According to the new Constitution, Montenegro was a constitutional but not a parliamentary monarchy. The introduction of the constitution and additional laws, as the Freedom of Press Law and the Criminal Law, paved the way for a modern legal framework in accordance with the standards of the Western European countries.