Jacques Vaillant ( 1625 - 1691 ) was a Flemish painter. Jacques Vaillant s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 6076.84 USD for PORTRAIT OF FREDERICK I OF PRUSSIA (1657-1713) in 2005 to 20000 USD for Portrait of a Boy as a Hunter, Holding a Boar Spear, with his Greyhound in 2018 , based on the size and medium of the art