The identity of the sitter as Jan de Witt (1625-1672) is traditional and has not yet been confirmed.  The style of the painting owes a great deal to Van Dyck, especially in his Antwerp period (q.v.).  De Crayer continued to paint in this style throughout his career.  The large ruff would suggest a date earlier than c1640 when such ruffs had gone out of fashion for men.

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