After the acknowledgement of Greece as an independent sovereign state, as defined by the Treaty of Independence (22 January/3 February 1830), two basic matters were pending: the definition of the frontiers and the appointment of a prince. As for the second matter, which reappeared after the resignation of Leopold, Duke of Saxe-Coburg, from the Greek throne on May 19/21, 1830, the three Powers suggested Otto, the second-born son of King Louis I (Ludwig) of Bavaria. The official nomination of Otto as king of Greece, an independent country under the regime of guaranty of the three Great Powers, was finalized with the Treaty of London (25 April/7 May 1832). At the same time, Britain, France and Russia would guarantee a loan of 60,000,000 francs. The choice of Otto was ratified by the Greek side in July 1832. The question of the constitution, to which Russia, France and Louis I were opposed, was still pending. A constitution was not granted and this matter was bound to be a basic difference between the Palace and the political powers, especially during the first decade of the newly-established Greek state (1833-1843).

As for the frontiers, the final settlement was achieved, after many consultations, with the Protocol of London in August 1832.
In July 9/21 1832 the three guarantor Powers and the Ottoman Empire signed the Treaty of Constantinople. This treaty defined that the north-western frontiers of the Greek state at the Amvrakikos Gulf, while the north-eastern frontiers, north of the Spercheios River in Lamia, remained undecided and the matter was referred to a new conference in London. The result of this conference was the Treaty of the 18th/30 August 1832. This treaty granted the region of Lamia to the Greek state and thus the Greek-Ottoman frontiers were defined between the Amvrakikos and Pagasitikos Gulfs. At the same time, forty million piastres was awarded as an indemnity to the Ottoman Empire, while the claim of the people of Samos and Crete to be integrated in the Greek state was rejected. The exact definition of the frontiers was completed in November and was approved by the Ottoman Empire in the middle of December 1832. About a month later, at the end of January 1833, Otto and his entourage arrived at the port of Nauplion, the capital of the first Greek state.