At present, it has become possible to believe that St. Andrew could have learned to work in Byzantium and Bulgaria in the early period of his life. In fact, many Russians visited the Balkan countries, Athos, Constantinople, the Holy Land, and often stayed there for a more or less long time. Thus, Athanasius Vysotsky, a disciple of St. Sergius, and undoubtedly personally known to St. Andrew, spent almost 20 whole years in Constantinople, working together with a group of other monks on the translation and copying of the works of the Church Fathers. In Constantinople there were also icons of Russian saints, in particular, there was an icon of Saints Boris and Gleb. Icons were also painted there specifically for the orders of the Russian Church: for example, in 1392 the already mentioned Athanasius Vysotsky brought to Russia the famous "Vysotsky tier" – a number of Deesis icons painted specifically for the Serpukhov Vysotsky Monastery founded by him. All experts agree that St. Andrew must have known these icons. It is known that iconographers sometimes accompanied ambassadors sent to Constantinople.

In the heritage of St. Andrew there is an image of a Greek sea vessel (in the fresco "The Earth and the Sea Give Up the Dead", Vladimir Assumption Cathedral, 1408), masts, yards, the hull of the ship, the flag on the stern – everything is painted with such a living knowledge of the ship's design, which is difficult to imagine in land Russia. One of two things can be assumed: either St. Andrew saw such ships himself, that is, he was at sea, or he adopted this information from his mentor, an artist of Greek origin. According to one of the hypotheses, St. Andrew is a disciple of the famous Theophanes the Greek. This hypothesis is based on the fact that in the record of 1405 their names are mentioned together, with Theophanes being the first. That Theophanes exerted a definite and perhaps considerable influence on St. Andrew can be considered indisputable, if only because they worked together for some time, and the younger Andrew, of course, carefully observed how the famous Greek worked. However, there is no indication of their closer cooperation. On the contrary, the fact that in the record of 1405 another master is mentioned among them – the elder Prokhor from Gorodets, who is not related to Theophanes, rather speaks of the absence of close contacts between Theophan and St. Andrew. There is no doubt that St. Andrew was fully armed with the culture of his time. The mobile way of life and the very character of Theophanes also speak rather against the possibility of systematic studies. Such an education, which made it possible to penetrate into the spiritual depths of phenomena, could most likely be obtained in the appropriate environment, primarily in Byzantium. Thus, the above hypothesis about the Greek education of the Monk Andrew is not unfounded. St. Andrew lived in an era of major historical events. He was a witness and, possibly, a participant in these events, often very difficult for Russia. In 1380, a bloody battle took place on the Kulikovo field, which marked the beginning of the liberation of Russia from the Tatar yoke. Two years later, Moscow was ravaged and burned by Tokhtamysh. It is likely that these events influenced the choice of the monastic path made by St. Andrew.

In 1395, Russia was subjected to a new invasion - this time it was attacked by the hordes of Tamerlane. Despite the readiness of Grand Duke Vasily Dimitrievich to repel the enemy, there was very little chance of victory due to the colossal numerical superiority of the enemy troops. There was only one hope left for the intercession of the Mother of God. A miraculous icon of the Mother of God was brought to Moscow from Vladimir. All the people, headed by Metropolitan Cyprian, came out to greet the holy icon at the place where Sretensky Monastery was later founded in memory of this event.

The Church called everyone to prayer, fasting and repentance. A miracle happened: the Mother of God appeared to Tamerlane (Temir-Aksak) in a dream and menacingly forbade him to go to Moscow. Reaching Yelets, Tamerlane turned back and disappeared as suddenly as he had appeared. Soon after this, Saint Andrew painted a copy of the icon of the Mother of God of Vladimir with the blessing of Metropolitan Cyprian.

The place of tonsure of Saint Andrew is not known for certain. But his whole life is connected with two monasteries - the Trinity-Sergius and the Spaso-Andronikov in Moscow. Tradition, dating back to the end of the sixteenth century, sees in St. Andrew the spiritual son of St. Nikon of Radonezh. However, modern research shows that he most likely took monastic vows in the Spaso-Andronikov Monastery. These two versions do not contradict each other in essence, since both monasteries were closely related to each other; it is obvious that Saint Andrew was in obedience to the Monk Nikon when he worked at the Trinity Monastery, and memories of this have naturally been preserved. Since the monk Andrei constantly fulfilled the orders of the metropolitan and the grand prince, it was natural for him to be, so to speak, "at hand," that is, in one of the Moscow monasteries, namely in the Spaso-Andronikov monastery. It is possible, however, that earlier relations unknown to us connected St. Andrew with the monastery of St. Sergius. In spirit, St. Andrew is an undoubted disciple of St. Sergius.

But even while staying at the Spaso-Andronikov Monastery, the monk Andrei lived in the spiritual environment of the disciples of the Monk Sergius, with whom he was in close contact during his trips related to the fulfillment of orders. In addition to the Monk Nikon, he apparently knew St. Savva of Storozhevsky, since at the turn of the fourteenth and fifteenth centuries he worked in Zvenigorod and somewhat later in the Savvino-Storozhevsky monastery itself. He must also have known the nephew of St. Sergius, St. Theodore, Archbishop of Rostov, who for some time was hegumen at the Simonov Monastery, next to the Andronikov Monastery. Another abbot of this monastery and an interlocutor of the Monk Sergius, Saint Cyril, departed in 1392 to Beloozero, but as a person he was undoubtedly known to the monk Andrew. Finally, a direct disciple of the Monk Sergius was the Monk Andronicus, the founder and first abbot of the monastery. Ties with the Trinity-Sergius Monastery were constant and diverse. Some monks moved from the Trinity Monastery to the Spaso-Andronikov. Among them was Ermola-Ephraim, who gave funds for the construction of a stone church, and the future abbot, with whom the monk Andrei was also in close relations. Saint Andrew undoubtedly knew Epiphanius the Wise, a direct disciple of Sergius, who wrote down the initial information about the Andronikov monastery and left information about Theophanes the Greek. Epiphanius did not write anything about the monk Andrew, which is quite natural, since he was telling about the past, albeit recent, and not about his contemporaries.

Living in a lofty spiritual environment, in an atmosphere of holiness, the monk Andrew learned both from historical examples of holiness and from the living example of the ascetics around him. He delved deeply into the teaching of the Church and into the lives of the saints whom he depicted, followed them, which allowed his talent to reach artistic and spiritual perfection.

In addition to Epiphanius the Wise, the monk Andrew knew well other highly educated people of his time, with whom he was in close contact. Among them, first of all, we should mention St. Cyprian, Metropolitan of Moscow. The monk Andrew was close to the spiritual world of Saint Cyprian, who went through the school of Athonite monasticism. Communication with him was quite close, since not only St. Andrew was interested in it, but also St. Cyprian, who was accustomed to the intellectual atmosphere of Byzantium and therefore singled out the most spiritual and educated Russians in Moscow. Through this communion, the spiritual genealogy of the Monk Andrew goes back to both chapters of the Athonite hesychasm, since Metropolitan Cyprian was a disciple of the holy Patriarch Philotheus, a disciple of St. Gregory Palamas, and a relative (as it is assumed) of St. Euthymius, Patriarch of Tarnovo, a disciple of St. Theodosius of Tarnovo, a disciple of St. Gregory the Sinaite. The elevation of the "mind and thought" to the "immaterial and Divine light" from the contemplation of holy icons ("the elevation of the sensual eye") – this completely hesychastic characterization was not accidentally given by St. Joseph of Volotsk to the Monk Andrew and his "companion" Daniel. There are probably not very many analogies for it in Russian hagiography.

Undoubtedly, the monk Andrew also knew well the holy Metropolitan Photius, who replaced the deceased Metropolitan Cyprian in 1409. Photius also belongs to the number of highly educated, spiritual and active hierarchs, to whom belongs a number of epistles, which the monk Andrew undoubtedly knew.

"Surpassing all in wisdom," in the words of the Monk Joseph, the monk Andrew was well acquainted with the works of many holy fathers and teachers of the Church. He undoubtedly knew the works of St. Dionysius the Areopagite, translated into Slavonic in the fourteenth century by the Athonite monk Isaiah on behalf of the supreme ecclesiastical authority in connection with the hesychastic disputes. The works of St. Gregory the Sinaite, accessible to the Russian reader, were also close to him. The reading circle of the enlightened man and, undoubtedly, of St. Andrew included the "Theology" of John of Damascus, the "Six Days" of John the Exarch, the "Expository Palea" and other works of Orthodox writers and Church Fathers.

In 1408, according to the chronicle, the Monk Andrew and Daniel painted the Dormition Cathedral in Vladimir. Under this year, the chronicles indicate: "In the same summer, on May 25, the painting of the great and cathedral church of the Most Pure Volodymyr was begun by order of the Grand Duke, and the masters were Danilo the icon-painter and Andrei Rublev."

In a short chronicle report, he draws attention to the fact that the date of the beginning of the painting is indicated. This is an exceptional case. Obviously, great importance was attached to the frescoes, which is explained by the expectation of the arrival from Constantinople of a new metropolitan, who, after the death of Cyprian in 1406, became Photius (in 1409).

Vladimir continued to be considered the city-residence of the metropolitan, and the city cathedral, accordingly, was a cathedral. Therefore, the metropolitan cathedral had to have paintings worthy of a high envoy of the Church of Constantinople, and to show no less dignity of the Russian Church. In this way, the iconographers carried out a kind of "representative mission", and their task was very difficult, if we take into account the exceptionally high requirements of the Greek Church of that time for church art, the requirements, first of all, of the spiritual witness to the truth in art, and hence its qualities. In addition, the expected metropolitan himself was undoubtedly a good connoisseur and connoisseur of church art, which follows from his Constantinople upbringing.

The high mission was entrusted to Daniel the Black and the Monk Andrew, who is mentioned by the latter as the younger. The iconographers worthily fulfilled the obedience entrusted to them.