(Link)
Grudziadz Polyptych
Holding Institution
Warsaw National Museum
From
Poland (exact location unknown)
Dating
1390

Panels from the Grudziadz Polyptych by the Master of Trebon altarpiece,c. 1390 Bohemia

Музей Війська Польського в Варшаві та музей у Гданську

(Link)
The Master of the Grudziadz Altarpiece was a Bohemian artist,[1] active at the end of the 14th and the beginning of the 15th century. His name is derived from an altarpiece which hung in the castle of the Teutonic Knights in Grudziadz (German: Graudenz), and may now be seen in National Museum in Warsaw.