The castle takes its name from a saint who spent his last days here in prayer and contemplation, after settling here when Cyprus was taken by Jerusalem’s Arabs. It is set approximately 660 metres above sea level. It is not known exactly when the castle was built but it is believed that it was constructed by the Byzantines in the 8th century AD in order to protect the island against Arab raids. The castle was first known as ‘Didymus’ which means ‘twins’ on account of the fact that it is built on two peaks. The Lusignan kings, who ruled Cyprus in the 13th century, made additions to the castle, which they used both as a military base and a residence. For this reason, although it is a Byzantine castle, most of it actually dates to the Lusignan period. In 1489, the Venetians who had invaded Cyprus, destroyed and abandoned the castle, as they considered it to be too far from the sea. St. Hilarion is built in three sections: the lower, middle and upper parts. In the lower section is the exterior entrance gate, the area known as the barbican which is surrounded by walls and protects the main entrance to the castle, the castle’s main entrance gate, assembly hall, water cistern, corner tower and the Lusignan stable block with its high arches, which is used as a museum. The middle section is reached through an entrance gate in the walls which were built in the Byzantine and Lusignan period. This part comprises the 10th century Byzantine church, royal palace chamber and passageway, roof terrace, kitchen, store room (pantry) and terrace. It also incorporates the four storeyLusignan royal palace which was used by the royal family as a winter residence until the end of the 13th century, the barracks and the Lusignan water cistern. The top section is built on two peaks. In this section can be found the Byzantine tower, kitchen and service buildings, the royal palace, additional rooms added to the royal palace in the 16th century together with the Queen’s window, which dates from Lusignan times, the water cistern and Prince John’s tower. Prince John was the younger brother of King Peter I and was one of those responsible for his death. Peter I’s wife, Queen Eleanor wanted to take revenge for his murder. In order to first win his trust, she took part in a peace ceremony which took place in Girne Castle and pledged to stay on good terms with him. Eleanor went to Lefkoşa and sent the prince a letter saying that the Bulgarian mercenaries who worked for him were planning to murder him and take control of the castle. Believing this to be true, Prince John went to the castle’s highest tower and called the Bulgarian soldiers to him one by one, and threw them from the tower. In the end only one remained alive. After this the Prince, who was now along at the castle, left for Eleanor’s Palace in Lefkoşa. After they had eaten a meal together, Eleanor showed the prince her husband’s blood-stained shirt, and then together with the other people who were waiting with her, one by one they stabbed him to death. In tears they took his body first to his home and then to St. Dominic’s church in Lefkoşa.