The exchange, however, was not executed. Grotius made a journey to Rheims, where the King was, to speak to him of it[396]. The King gave him the most positive promises, and engaged to give John de Vert his liberty, if the Duke of Bavaria sent Marshal Horn to Landau. Grotius wrote to the Court of Bavaria; John de Vert was conducted to Selesdad: and at last the exchange was made at Strasbourg. Grotius wrote a letter[397] of compliment on it to the Marshal, and desired him to come and lodge with him, if he purposed to pass through Paris in his way to Sweden. FOOTNOTES: [392] Bougeant, l. 6. sec. 14. [393] Ep. 1259. p. 371. [394] Ep. 1263. p. 573. 1276. p. 578. [395] Ep. 1414. p. 645. [396] Ep. 1512. p. 685. 1517. p. 687. 1523. p. 690 & 1532. p. 693 [397] Ep. 1565. p. 708. IX. The renewal of the treaty of alliance between France and Sweden, which was almost expired, was now on the carpet. This grand affair was negotiating at Hamburg between Claude de Meme count d'Avaux, and John Adler Salvius, Vice-Chancellor of Sweden. Grotius[398], who was attentive to give such counsels as might be useful to the crown of Sweden, wrote to the High Chancellor on the 29th of September, 1640, that if the subsidies made the only difficulty to the conclusion of the treaty, he knew the Cardinal would augment them. And accordingly, instead of a million, which France promised to Sweden by the last[399] treaty, by this she gave her twelve hundred thousand Francs. The negotiation meeting with many obstacles, it was drawn into a great length and not concluded till the last of June, 1641.