When Blake found Rupert at anchor in the Tagus, he made a demand for his surrender. A diplomatic agent was landed to represent the case of the British Parliament to the King of Portugal. King John was in a cruel position. He could not surrender Rupert without a certain amount of disgrace. Indeed he was so feeble that the Royalist adventurers would have been formidable enemies. Rupert had no scruple as to treating his host with scant politeness, and there was a party at the Portuguese Court in favour of helping the Royalists. On the other hand, the king had fair warning that if he did not treat Rupert as a pirate, the Parliament would ruin his commerce. While the king was vacillating, the two fleets remained at anchor not far from one another, and their sailors had frequent conflicts. An unsuccessful attempt was made by the Royalists to blow up Blake's flagship by a torpedo. When Blake found that the Portuguese Government was not yet ready to help him against the Royalists, he proceeded to prove to it the danger of the course it preferred. His station at the mouth of the Tagus enabled him to lay hands easily on all ships coming in or going out. When the outward-bound Brazil fleet put to sea, it was found to include several English vessels freighted by the Portuguese. These Blake pressed for the service of the Commonwealth, and sequestered their cargoes. The blow was a sharp one, and was not made more palatable by an intimation that it was only a warning, and that worse would follow if the Portuguese persisted in their ill-advised courses. The king was not unnaturally very angry, and appealed to Rupert to help him in driving off Blake's squadron. Nothing could have been more to the taste of the Royalist admiral, and if there had been any effective Portuguese fleet to help, he would have helped it. But there was not, and therefore when Rupert put to sea no battle took place. Rupert hoisted the Royal Standard and made a bold show. But in reality he could not venture to do more than skirmish with the overwhelming force opposed to him. Blake had been joined by Popham, and their combined force was not less than twenty vessels. The three capital ships and four small frigates of Rupert's own following were no match for such an antagonist. Therefore, although Rupert came near enough to have his topmast shot away, he could not venture to do much more than skirmish at a moderate distance from the forts, when the wind blew from a direction which gave him security that he could get safely back again.