The Extraordinary Works of Russia's Greatest Icon Painter, Andrei Rublev (1360 - 1430)
There is an opinion – I do not remember who expressed it – that people in the 15th century had such a thirst and need for God and that Andrei Rublev was able to write such an icon of the Holy Trinity, that a 15th-century Church synod issued a decree ordering all icon painters to portray the Holy Trinity the way Andrei Rublev had done.