Van Hillegaert is known for his landscapes, military scenes and equestrian portraits. His earliest known work dates from 1619. He painted the important sieges of the
Eighty Years' War led by the Princes of Orange
Maurice and
Frederick Henry. He depicted two of Prince Maurice's key military successes: the victory at the
Battle of Nieuwpoort in 1600 and the disbanding of the ‘Waardgelders’ in Utrecht in 1618. He further painted the
Siege of 's-Hertogenbosch of 1629, an important victory for Prince Frederick Henry. He also created equestrian portraits of the two Princes and other dignitaries. His military scenes are closely related to those of the Dutch painter Henri Ambrosius Pacx and, to an extent, the Flemish painter
Pieter Snayers. He often executed multiple versions of paintings as he likely worked mainly for the open market and less often on commission for the House of Orange or official institutions. For instance, four known version of the ''Siege of 's-Hertogenbosch'' are known. He may have added the figures in a landscape by Alexander Keirincx. A number of landscape drawings, some of Italianate landscapes, have been attributed to the artist. ==References==