[1] He was proclaimed Prince of Achaea during the great Morean revolt of 1453-54 and was recognized as such by the King of Naples, the Republics of Venice and Genoa, and the Papacy.

During the arrangements, Centurione ensured that his heir John would retain his princely title even only by name..[6] He died in 1432 and the last remnants of the principality of Achaea passed to the despotate of Morea.

[10] The Byzantine contemporary historian George Sphrantzes recorded the renovation of the Principality in the following short passage: "At Morea, the brother in law of Thomas, the son of Prince Centurione, had escaped from the prison of the Chlemoutsi Castle causing disruption to the region, while the Sultan was concentrated against Serbia"[11].

The Venetian Doge Francis Foscari and King Alfonso V of Naples sent John congratulation letters, recognising him as "Prince Centurione III".

[12] John achieved the support of many Latins, Greeks, and Albanians and with them compromising his army, he besieged the city of Patras under Thomas's rule.

Later in 1457 the Venetian Republic recognising his high political value as titular Prince of Morea granted him an annuity, on the condition John would continue to reside in Modon or wherever else he could be most useful to the designs of Venice.

Seven years later, in 1464, after the complete annexation of Morea to the Ottoman empire, we find John moving to Rome where he managed to secure only a monthly pittance from Pope Paul II.

In this she is mentioned as "the most majestic woman Magdalene Asenina Zaccaria" (having adopted the family names of John) and also receives recognition of her title as Princess of Achaea.

It was in Hopf's genealogical account of the Zaccaria family that stigmatized John as a bastard descendant, without providing the evidence that led him to this conclusion.