Nikousios was very well educated, having received instruction by the Jesuits in Chios, and gone on to attend the Patriarchal Academy in Constantinople and the University of Padua, where he studied medicine.
He played an important role in the negotiations that ended the long Siege of Candia in 1669, and amassed a great library with many valuable manuscripts.
His appointment as Grand Dragoman marks the start of the Phanariotes' rise to high political offices in the Ottoman government.
After his death in 1673, this document was put forward against the rival claims of the Catholics, supported by the French ambassador, the Marquis de Nointel.
[1] Nikousios apparently married twice, the first time around 1655 to a lady from the Cantacuzino family, with whom he had a son and a daughter.