Portrait of a Dutch Commander (?)

We don‘t know who painted this picture, nor do we know who the sitter is, but his upright stance and direct gaze and the immaculate points of his handsome moustache suggest a man used to authority. The commander’s baton in his right hand confirms his likely rank in the Dutch army.The picture has been much darkened by age and coats of varnish, but it is possible to see the white lace of his collar and cuffs and the wide sash over his shoulder that holds his sword sheath suspended behind him. He supports the pommel of the sword with his left hand.The building in the background appears to be the Castel Sant’Angelo in Rome. Perhaps this was the Commander’s choice to remind him of a visit to the city, since it’s unlikely that it was painted when he was actually there.