Jan Gregoire ( 1887 - 1960 ) was a Dutch painter. Jan Gregoire s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 16.73 USD for Portret van Henri Winters in 2006 to 638.22 USD for A bird's-eye view of the Vrijthof, Maastricht in 2011 , based on the size and medium of the artwork.