The new state was not recognized by the Great Powers of the day, which, after initial successes, was threatened with collapse both from within due to civil war and from without through the victories of the Turco-Egyptian army of Ibrahim Pasha.

Ottoman refusal to accept these terms led to the Battle of Navarino, which effectively secured complete Greek independence.

In 1827, the Third National Assembly at Troezen established the Hellenic State (Ἑλληνικὴ Πολιτεία) and selected Count Ioannis Kapodistrias as Governor of Greece.

After his arrival in Greece in January 1828, Kapodistrias actively tried to create a functional state and redress the problems of a war-ravaged country, but was soon embroiled in conflict with powerful local magnates and chieftains.

The Fifth National Assembly at Nafplion drafted a new royal constitution, while the three "Protecting Powers" (Great Britain, France and Russia) intervened, declaring Greece a Kingdom in the London Conference of 1832, with the Bavarian Prince Otto of Wittelsbach as king.