With whom did the Renaissance painter Jan van Eyck paint the 3.5 m tall altar at Ghent?

Explanation

Jan van Eyck (1385-1441) was a Flemish Renaissance painter. He painted the 3.5 m tall altar at Ghent in the church of Sint-Baafs with his brother, the painter Hubert van Eyck (1370/1375-1426). The piece ushered in a new realism in Northern European art. Jan van Eyck is considered one of the masters of Flemish art.