The (Bourtzi) Island Castle and the islet of Lazaretto which I can see below me, close to Plaka was first recorded as being built in the times of Byzantium.

In the Dynasty of Heracleus C 600AD, at the similar time of the Prophet Mohammed. Within 5 years of his death in 623 AD, a wave of Arabic tribes under the command of Mu’Awiya a close relation of the Prophet Mohammed himself, invaded Syria, Damascus, Persia and connecting countries. Also at that time, the Arab fleet took possession of a string of islands including Rhodes and Chios and was constantly harassing the Anatolian coast and penetrated into the Aegean. That is why and when the castle of Agios Constantine, with its church on the top, was built in 640 AD: to protect the valuable harbour and the hinterland and olive groves of Poros, Galatas and Trizinia.

There was also the priceless thousands of lemon trees and copious springs of water that I can see if I turn to my right on Belessi hill.
Constans II was the Emperor of the Byzantine Empire and he was busy defending his borders in Sicily when he was assassinated. Constantine IV, his son ruled from 668 to 685 having cut off his two brothers noses and ears or split their tongues, so they would be ineligible to rule!

Things finally came to a head when, in 674AD the Arab Fleet came into the Sea of Marmara and right up the city walls of the capital of Constantinople and tried to storm city. At the same time Slav army was invading Macedonia. Constantine ordered the Byzantine fleet to repel the Arabs. They came out with a new weapon.

A Syrian Greek Christian refugee from Heliopolis, Kallinicos was Believed to have Invented this  “secret weapon” * in about 673 AD. It was the first that  “Greek Fire,” probably a mix of combustible Sulphur, oil, Quicklime, naphtha and calcium phosphate. ** Projected through a Syringe (Siphonarios) by bronze pipes, was used on the sea and the victory was decisive in a naval Battle nearby the city of Syllaeum in 678AD. The Slavs were defeated too and for 30 years the Byzantines were not threatened. But Constantine agreed to pay 3.000 pieces of gold a year.
Through the years the castle of Agios Constantine was owned by the Venetians and then the Ottoman Turks and was named Bourtzi. Finally in 1821 with the pent up fury of almost 400 years of bloody occupation, after the victory of Kalamata and the massacre of Tripolis where 10,000 Turks were slain, the Greeks took the whole area in their Battle of Independence with the help of a coalition of Russian, French and British fleets, Destroying the Ottoman fleet at the battle of Navarino.

Capodistria the Governor of the Greece set up his government at Trizinia and commanded the Bourtzi to be rebuilt in 1827 by a Bavarian, K Heideck, to defend the fleets. According to the Director of the Poros Library Iannis Maniatis, the church of Agios Constantine was still standing, under the supervision of the Monastery of Zoodochos Pigi. But the Architect Heideck was badly in need of stone so he dismantled the church on the promise that he would replace it after the monks had removed all the relics and Icons.

However the church has never been built. And further embarrassing times were to befall the castle. Unfortunately in 1831 an argument arose about government resources and a group of communities including Mani, and Hydra, with Admiral Miaoulis heading his fleet. The admiral assaulted the Bourtzi, blew it up and took possession the several ships of the fleet. However, the Greek Government was reconciled at Napflion.

And there the castle of Agios Constantine lays, a ghostly echo………

Of sentries on the ramparts trumpet and drum… And of glittering Roman uniforms (they were Greeks, but they called themselves Romans). Or perhaps is it an answering   bugle call from the Hellenic Naval Collage at Poros? Sword and Sandal with waving horsehair helmet, breastplate, spear and shield, atop a golden Imperial Standard. A Byzantine Galley sailing through.