The Dermoyen family included a number of prominent weavers and dealers of Brussels tapestry in the 1500s.
Jan and Willem were weavers of large tapestries, in some cases for royal and imperial courts.
Jan and Willem are credited with leading the weaving of the Battle of Pavia tapestries in about 1528 to 1531. In this, they worked with Bernard van Orley.
Jan and Willem also led the weaving of the Hunts of Maximilian tapestries in about 1531 to 1533.
Jan is credited as having led the weaving of the Story of Cyrus tapestries that are now in the Isabella Stewart Gardner Museum.