The Holy Trinity Monastery was founded in 1990 by Elder Johannes and in the following years was built together with the first monks from their own means and by their own hands. In the meantime, the sanctuary is sustained by a second generation of monks. The line of monastic tonsure of the Great Schema, which is handed on in the Holy Trinity Monastery, can be traced back through many generations. It leads through Elder Daniel of Katounakia (early nineteenth century) to the region of the Great Lavra and to St Athanasios the Athonite.

In the 1970s Father Johannes studied music in Berlin, later religious studies and Byzantine studies. Having come into contact with Orthodoxy in 1974, he regularly attended the Orthodox services and began the practice of the prayer of the heart. In 1981 he became a monk on the Holy Mountain of Athos and there, in August 1984, received the monastic tonsure of the Great Habit (Great Schema).

With the blessing of his elder, in 1985 he began the choral office together with two fellow brothers in a provisional monastic apartment in what was then West Berlin and prepared the foundation of the monastery. Life moved for several years between Athos and Berlin.

In the year of German reunification, 1990, the monks purchased the land in Buchhagen and began building the German Orthodox sanctuary.

Unforeseen resistance stood in the way of the founding of the monastery; endless difficulties had to be overcome. Yet by the grace and blessing of the Holy Trinity, the help of the all-holy Mother of God Mary, and the Holy Fathers, many wonders also occurred.

In August 1994 the monastery was consecrated by His Eminence Symeon, Metropolitan of Western and Central Europe, as a German Orthodox abbey within the communion of the Bulgarian Patriarchate. During the next two years the crypt of the monastery church was built and in 1996 was likewise consecrated as a temple of Divine Wisdom.

From 1999 to 2002 the Michael Tower and the northern monastery wall with the Mary Tower were built.

From 2004 to 2009 the holy water fountain was constructed, and in 2013 and 2014 the entrance area was redesigned.

The monastery has become an integral part of the region. The people in the surrounding area esteem the monks and rejoice whenever they see one of the fathers in town. They know that when the bells ring down from the mountain into the valley, chanting begins in the sanctuary and the monks pray for the country and for the people. Some Orthodox faithful have moved into the district of Holzminden because of the monastery in order to participate regularly in the divine services. Many visitors from Germany and many other countries are drawn again and again to the monastery in Buchhagen, where they also find good accommodation in hotels and guesthouses in the surrounding area.

In February 2013 the election of the new Patriarch of Bulgaria took place. As abbot of the German monastery, Elder Johannes belonged ex officio to the roughly 150 persons entitled to vote and travelled together with the other fathers to Sofia for this great event. His Holiness Neophyt was elected as the new Patriarch and was enthroned in a magnificent celebration in the Sofia Cathedral in the presence of numerous metropolitans and bishops from all Orthodox lands of the world (Monastery Letter 2013).

Likewise, in the election of the Metropolitan of Western and Central Europe, the abbot of Buchhagen belongs ex officio to the electoral body. After our highly revered and beloved Metropolitan, His Eminence Symeon, finally stepped down in August 2013 for reasons of age, His Eminence Gregory of Tărnovo organised the election of the successor. His Eminence Antonios was elected by a large majority and on 3 November 2013 was solemnly enthroned in the presence of his predecessor, His Eminence Symeon, many other metropolitans and bishops, the ecclesiastically anointed King of Bulgaria Simeon II, the Bulgarian ambassador, and many honoured guests. Since then Fr Abbot Johannes has been a permanent member of the diocesan council. His Eminence Metropolitan Antonios continues the work of his predecessor with admirable responsibility, dedication, and spiritual bearing; he has succeeded in consolidating the diocese in many respects. He visited the monastery for the first time in December 2014; the relationship is marked by special mutual esteem and trust.

At the request of our Elder Johannes, the very reverend Father Symeon, who besides many other tasks has already been serving for several years as priest and confessor, was elevated to the rank of archimandrite in December 2014.