Saint John was born in Istanbul in the middle of the 12th century, to rich and pious parents. The presence of John of Kaloktenis on the metropolitan throne of Thiva gave new impetus to the church life of the Boeotian area and the development of the region.

Saint John Kaloktenis, this enlightened religious man founded monasteries and converted the male monastery of the Virgin Mary into a female one (the monastery of Decani, after the name of the first abbess). He founded churches in Thiva, among which the church of Glorious Virgin Mary. On his own initiative, a hospital, a nursing home, a workhouse and a shelter for the poor were founded.

He also had the flow of Ismenos River diverted towards the plain. Thus, the supply of the twenty water mills of the area, that were used for the irrigation of crops, was facilitated. In the course of his efforts to improve the social status of women, we already know that Kaloktenis created a school (girls’ school) for the education of girls. This was uncommon and very innovative that time. The Church declared him a Saint and his beloved Thiva honours him as its Patron Saint, in his homonymous Church in the centre of the city on April 29th.

The present church was built around 1900 at the expense of Queen Olga, in place of an older one. According to the tradition, the first church was founded by Kaloktenis himself. It was dedicated to Theotokos where it is believed that the holy relics of the Saint were laid down. During the excavation work for the opening of the foundations of the Drakeios Night School (former Town Hall of Thiva) the ruins of this first church of the Virgin Mary were revealed. A fresco representing the Entrance to Jerusalem was detached from there and is exhibited in the Museum of Thiva.

In the course of his efforts to improve the social status of women, we already know that Kaloktenis created a school (girls’ school) for the education of girls, which was uncommon that time.