Sergiev-Posad began from the Trinity-Sergius Monastery which was founded in the middle of the 14th century. Due to its historical record and architectural merits, the Sergiev-Posad Laura (monastery of the first rank) has become one of the most famous and popular treasures of Russian antiquity. Its founder St Sergius, once a boyar in Rostov-the-Great, after taking orders was known under the name of Sergius of Radonezh.
From his first years at the monastery St Sergius was an active supporter of the policy, which was pursued by the Grand Princes of Moscow. The position and authority of the Trinity-Sergius Monastery were further consolidated when St Sergius proclaimed his support for the national cause - the rallying of all Russians for the struggle against the Tartar domination. The consent and blessing of St Sergius were begged by Grand Prince Dmitry who came to the monastery before he started off with army to the Kulikovo Field.
The Trinity-Sergius Monastery was an important center of cultural activity in ancient Russia.
The monastery's oldest stone building, the Cathedral of the Trinity, was erected during 1422-23. It is a comparatively small, single-domed temple. The monastery built it as a memorial church over the grave of St Sergius thus paying homage to the inestimable service of its first abbot. The frescoes and icons were commissioned to the most highly regarded artists of the time, Andey Rublyov and Daniil Chyorny. It was for this church that Andrey Rublyov painted his famous icon The Old Testament Trinity. The surviving icons of that time now fill up the tree of iconostasis.
When the practice of stone construction was resumed, one of the first to be raised was the Church of the Holy Ghost (1476).
The works on the new-domed Cathedral of the Assumption started in 1559, and the tsar himself was present at the ceremony of laying the first stone. By sight the Cathedral of the Assumption looks very much like its Moscow counterpart - the Cathedral of the Assumption in the Kremlin, though it has somewhat larger dimensions that the latter. The frescoes in the interiors were executed a century later --in 1684.
In the 16th century, the construction of stone buildings proceeded both of the monastery grounds and in the surrounding countryside. Two churches were built near the monastery, on the slope of a hill - the Church of the Presentation of the Virgin and the Church of St Parasceve Piatnitsa (Friday). Standing closely together they appear to be parts of one architectural whole.
The years of 1635-37 were marked by the construction of a group of buildings including the Infirmary and the Church of Sts Zosima and Sabbatius.
Of the additions made at the end of 17th century the most important were the massive buildings of the Refectory with the Church of St Sergius and the Tsar's Palace. They stand on either side of the passage leading to the monastery's central square. The outer decor of the Refectory is strikingly rich and sumptuous.
The buildings that made the ensemble complete were erected in the 18th century. Among them was the bell-tower of 1740-70s, which has united all these architectural monuments belonging to different epochs into a single whole.
The fine specimens of national architecture forming the ensemble of the Trinity-Sergius Monastery make it an open-air museum of architectural forms and styles.