Andrés Marzal de Sas, or Andreu Marçal de Sax (fl. 1390-1410),
• Was a painter of Dutch origin who worked in Valencia.
• Based on his name, he was from Sas van Gent, although some sources indicate he may have been from Saxony.
• Between 1393 and 1399, he collaborated with Pere Nicolau.
• His only documented work is a "Doubting Thomas", now in the museum of Valencia Cathedral.
• Together with Pere Nicolau, he is considered to be a major representative of the International Gothic style and helped introduce Early Netherlandish painting to Spain.
• He also worked with Guerau Gener from 1405 to 1407, and with Gonçal Peris Sarrià, in 1405, for a Nativity altarpiece.
• His influence on Gener is apparent in the Gothic altarpiece of Santes Creus, which Gener painted with Lluís Borrassà.
• A document from 1410 indicates that he was awarded a pension by the City Council, as he had become ill and fallen into poverty.
