Family and Background
Tbeli was born around 1190 into the noble Abuseridze family. His father, Ivane (called John in some accounts), held the title of eristavt-eristavi, or archduke, of Upper Adjara; according to the tradition recorded of his life, he was killed fighting the Turks. After her widowhood, Tbeli's mother took monastic vows under the name Ekaterine (Katherine).
Tbeli had two brothers, Abuseri and Vardan (also given as Bardan), described as prominent figures of their day. Tbeli himself is said to have had seven children. He received an education befitting his noble rank and was associated with the intellectual life of the Gelati Academy, where he gained the broad learning that shaped his later scholarly work.
Scholarly and Liturgical Work
Saint Tbeli left a notable mark on Georgian culture as a hymnographer, an astronomer, an expert in sacred music, and a scholar of diverse interests. Among his liturgical works is a hymn collection dedicated to Saint John the Baptist, Saint John the Theologian (the Evangelist), and Saint John Chrysostom.
His principal scholarly treatise, known as 'The Complete Timekeeper' (also rendered as a chronicon with full account and order), addressed problems of chronology and the calendar. It treated different systems for keeping time, the dates of ecclesiastical feasts, tables of moonrise and moonset, and special cycles. The work rested largely on his own mathematical investigations rather than on direct astronomical observation, reflecting his command of the science of his age.
Some scholars hold that Tbeli served as bishop of Tbeti, the see from which his appellation 'Tbeli' is thought to derive, though other accounts of his life describe him only as a clergyman and do not name him a bishop.
The Church at Khikhani and His Chronicle
Tbeli built a church in honor of Saint George in the village of Khikhani in Upper Adjara, where he served and is thought to have composed most of his works. His hagiographical work, 'The New Miracle of the Great-martyr George', preserves valuable historical information about his own family and the efforts of the Abuseridze house to sustain Georgian culture during the feudal epoch, and includes a testament and account of his ancestry.
Veneration
The Georgian Apostolic Church has numbered Saint Tbeli Abuseridze among the saints in recognition of his service to the Church and its people. He is commemorated on August 17 (August 30 on the civil calendar). A church dedicated to him stands in Batumi.