St. Andrei Rublev the Iconographer
Troparion - Tone 3
Shining with the rays of divine light, O venerable Andrew, You knew Christ the wisdom and power of God. By means of the image of the Holy Trinity You preached to all the world the Holy Trinity in unity. And we, with amazement and joy, cry out to you: As you have boldness before the Most Holy Trinity Pray that the Uncreated Light May illumine our souls!
Kontakion - Tone 2
Like a trumpet, you clearly sounded the sweetness of divine hymns, and were revealed as a brilliant beacon shining on the world with the light of the Trinity. Therefore, we all cry to you, venerable Andrew: "Unceasingly pray for us all."