Born in Ryakia, Diamantis Nikolaou Olympian was the eldest son of the great armatolos and klepht Raideniotis (Ryakiotis) Olympios, best known as Nikolas Kateriniotis Olympios.
He operated in the mountains of Vermio, Olympus and Pieria before 1821 and after the outbreak of the Revolution.
The interim government and the Supreme Court because of his bravery and military skill appointed him commander of Evia and Eastern Greece.
He successfully confronted the Turks in Evia and in the battle of Faucets.
In July 1829 he represented Thessalomakedones fighters in the Fourth National Assembly at Argos and offers to Kapodistrias their proxy.