 However, he was persuaded by an envoy of the Princess Carolina of Orange-Nassau, sister of the Prince of Orange, to go instead to The Hague and to present the children to her, as official guests of the court.After the party's landing at Calais there was a month's delay at Lille, as first Wolfgang fell sick with tonsillitis, then Leopold suffered prolonged dizziness attacks.Early in September the family moved on to Ghent, where Wolfgang played on the new organ at the Bernardines chapel; a few days later he played on the cathedral organ at Antwerp.