Historical Context
The prince is identified with Ivan (John), a son of Andrey Vasilyevich Bolshoy (1446–1493), Prince of Uglich, who was himself the third son of Vasily II of Moscow. Andrey inherited Uglich, Zvenigorod, and Bezhetsk on his father's death in 1462, and his relations with his elder brother, the Grand Prince Ivan III of Moscow, deteriorated over questions of succession and the privileges of the boyars.
When Andrey disobeyed an order to support an ally in 1491, Ivan III summoned him to Moscow in 1492 and had him arrested; Andrey died in prison in 1493. Following his arrest, his sons Ivan and Dmitry were imprisoned in Vologda, while their appanage of Uglich was annexed into Muscovy. The synaxarion's account of John and his brother Demetrius being imprisoned by their uncle, the Grand Prince John (Ivan III), corresponds to this history.
Given the recorded span of thirty-two years of imprisonment from around 1492, John would have remained confined until roughly 1524–1525, consistent with the sixteenth-century dating recorded in the saint's data. His commemoration alongside saints of the Vologda region accords with the historical detail that Andrey's sons were imprisoned in Vologda.