Otto of Greece in the context of "London Conference of 1832"

The Kingdom of Greece (Greek: Βασίλειον τῆς Ἑλλάδος, romanized: Vasíleion tis Elládos, pronounced [vaˈsili.on tis eˈlaðos]) was the Greek nation-state established in 1832 and was the successor state to the First Hellenic Republic. It was internationally recognised by the Treaty of Constantinople, where Greece also secured its full independence from the Ottoman Empire after nearly four centuries. It remained a Kingdom until 1924, when the Second Hellenic Republic was proclaimed, and from the Republic's collapse in 1935 to its dissolution by the Regime of the Colonels in 1973. A referendum following the regime's collapse in 1974 confirmed the effective dissolution of the monarchy and the creation of the Third Hellenic Republic. For much of its existence, the Kingdom's main ideological goal was the Megali Idea (Greek: Μεγάλη Ιδέα, romanized: Megáli Idéa, lit. 'Great Idea'), which sought to annex lands with predominately Greek populations.

King Otto of the House of Wittelsbach ruled as an absolute monarch from 1835 until the 3 September 1843 Revolution, which transformed Greece into a constitutional monarchy, with the creation of the Prime Minister as head of government, universal male suffrage and a constitution. A popular insurrection deposed Otto in 1862, precipitating the gradual collapse of the early Greek parties (English, French, Russian), which had dominated Greek politics.

The Kingdom of Greece was ruled by the House of Wittelsbach from 1832 to 1862 and by the House of Glücksburg from 1863 to 1924 and, after being temporarily abolished in favor of the Second Hellenic Republic, again from 1935 to 1973, when it was once more abolished and replaced by the Third Hellenic Republic.

Only the first King, Otto, was actually styled King of Greece (Greek: Βασιλεὺς τῆς Ἑλλάδος). His successor, George I, was styled King of the Hellenes (Greek: Βασιλεὺς τῶν Ἑλλήνων), as were all other modern Greek monarchs.

The Treaty of Constantinople signed on 21 July 1832 and was the product of the London Conference of 1832 which opened in February 1832 with the participation of the Great Powers (Britain, France and Russia) on the one hand and the Ottoman Empire on the other. On 21 July 1832 British ambassador Sir Stratford Canning and the other representatives concluded the Treaty of Constantinople, which set the boundaries of the new Kingdom of Greece along the Arta–Volos line.

Under the Treaty of London signed on 7 May 1832 between Bavaria and the protecting Powers, and dealing with how the Regency was to be managed until Otto reached his majority (while also concluding the second Greek loan, for a sum of £2,400,000 sterling), Greece was defined as an independent kingdom, with the Arta–Volos line as its northern frontier.

The Megali Idea (Greek: Μεγάλη Ιδέα, romanized: Megáli Idéa, lit. 'Great Idea') is a nationalist and irredentist concept that expresses the goal of reviving the Byzantine Empire, by establishing a Greek state, which would include the large Greek populations that were still under Ottoman rule after the end of the Greek War of Independence (1821–1829) and all the regions that had large Greek populations (parts of the southern Balkans, Anatolia and Cyprus).

The term appeared for the first time during the debates of Prime Minister Ioannis Kolettis with King Otto that preceded the promulgation of the 1844 constitution. It came to dominate foreign relations and played a significant role in domestic politics for much of the first century of Greek independence. The expression was new in 1844 but the concept had roots in the Greek popular psyche, which long had hopes of liberation from Ottoman rule and restoration of the Byzantine Empire.

The 3 September 1843 Revolution (Greek: Επανάσταση της 3ης Σεπτεμβρίου 1843; N.S. 15 September) was an uprising by the Hellenic Army in Athens, supported by large sections of the people, against the autocratic rule of King Otto. The rebels, led by veterans of the Greek War of Independence, demanded the granting of a constitution and the departure of the Bavarian officials that dominated the government. The revolution succeeded, ushering the period of constitutional monarchy (under the 1844 constitution) and universal suffrage in Greece.

The first constitution of the Kingdom of Greece was the Greek Constitution of 1844. On 3 September 1843, the military garrison of Athens, with the help of citizens, rebelled and demanded from King Otto the concession of a Constitution.

The Constitution that was proclaimed in March 1844 came from the workings of the "Third of September National Assembly of the Hellenes in Athens" and was a Constitutional Pact, in other words a contract between the monarch and the Nation. This Constitution re-established the constitutional monarchy and was based on the French Constitution of 1830 and the Belgian Constitution of 1831.

King Otto of Greece was deposed in a popular insurrection in October 1862. Starting on 18 October in Vonitsa, it soon spread to other cities and reached Athens on 22 October.

The Russian Party (Greek: Ρωσικό Κóμμα), presenting itself as the Napist Party ("Dell Party", Greek: κόμμα των Ναπαίων), one of the early Greek parties, was an informal grouping of Greek political leaders that formed during the brief period of the First Hellenic Republic (1828–1831) and lasted through the reign of King Otto. The parties of that era were named after one of the three Great Powers who had together settled the Greek War of Independence in the Treaty of Constantinople (1832). The three rival powers, the Russian Empire, the United Kingdom and July Monarchy France came together in order to check the power of the other two nations.

The Russian Party had considerable power, enjoying privileged access to the Orthodox Church, the state machinery, military leaders, and Peloponnesian political families; but it was also popular with a significant section of the common people who wanted a strong centralized government to crush the power of the Greek shipping magnates and the rest of the business class, which followed the English Party.