Born into a noble family from Corfu, he held the title of Count of Capo d'Istria and became a member of the island's Great Council.

[14] Kapodistrias, accompanied by his son Augustinos, was one of the twelve delegates drawn from the noble classes of the Ionian Islands in 1799 that were to be sent to Saint Petersburg and Constantinople, in order to negotiate the status of the new state.

[15] In September 1799, Kapodistrias and the Zakynthian Count Nikolaos Gradenigos Sigouros Desyllas were chosen by the Sublime Porte as representatives during the negotiations in Constantinople.

Although its status as a semi-independent republic under Ottoman sovereignty was unpopular,[18][19] it was nevertheless regarded as the first free Greek state to be established since the Fall of Constantinople in the 15th century.

[21] As imperial commissioners, the two men were responsible for watching over the implementation of the constitution, a position which was soon held by Antonios Maria's son Ioannis Kapodistrias.