might be allowed to attack the pirate at his anchorage, he received from the king of Portugal a peremptory refusal; and, in his attempt to force his way up the river he was driven back by the fire from the batteries.  In obedience to his instructions, he revenged himself on the Portuguese trade, and Don John, by way of reprisal, arrested the English merchants, and took possession of their effects.  Alarmed, however, by the losses of his subjects, he compelled[a] Rupert to quit the Tagus,[1] and despatched[b] an envoy, named Guimaraes, to solicit an accommodation.  Every paper which passed between this minister and the commissioners was submitted to the parliament, and by it approved, or modified, or rejected.  Guimaraes subscribed[c] to the preliminaries demanded by the council, that the English merchants arrested in Portugal should be set at liberty, that they should receive an indemnification for their losses, and that the king of Portugal should pay a sum of money towards the charges of the English fleet; but he protracted the negotiation, by disputing dates and details, and was haughtily commanded[d] to quit the territory of the commonwealth.  Humbling as it was to Don John, he had no resource; the Conde de Camera was sent,[e] with the title of ambassador extraordinary; he assented to every

[Footnote 1:  Thurloe, i. 134, 142, 155.  Heath, 254, 256, 275.  Whitelock, 406, 429, 449, 463, 475.  Clarendon, iii. 338.  Rupert sailed into the Mediterranean, and maintained himself by piracy, capturing not only English but Spanish and Genoese ships.  All who did not favour him were considered as enemies.  Driven from the Mediterranean by the English, he sailed to the West Indies, where he inflicted greater losses on the Spanish than the English trade.  Here his brother, Prince Maurice, perished in a storm; and Rupert, unable to oppose his enemies with any hope of success, returned to Europe, and anchored in the harbour of Nantes, in March, 1652.  He sold his two men-of-war to Cardinal Mazarin.—­Heath, 337.  Whitelock, 552.  Clarendon, iii. 513, 520.]

[Sidenote a:  A.D. 1650.  October.] [Sidenote b:  A.D. 1650.  Dec. 17.] [Sidenote c:  A.D. 1651.  April 22.] [Sidenote d:  A.D. 1651.  May 16.] [Sidenote e:  A.D. 1652.  July 7.]

demand; but the progress of the treaty was interrupted by the usurpation of Cromwell, and another year elapsed before it was[a] concluded.  By it valuable privileges were granted to the English traders; four commissioners,—­two English and two Portuguese, were appointed[b] to settle all claims against the Portuguese government; and it was agreed[c] that an English commissary should receive one-half of all the duties paid by the English merchants in the ports of Portugal, to provide a sufficient fund for the liquidation of the debt.[1]