peace with England as well. By 1598 the war had become long and costly for Spain. England and Dutch Republic too were war-weary and both sides felt the need for peace. However, in peace negotiations at Boulogne in 1600, Spanish demands were adamantly rejected by the English and Dutch. Nevertheless, diplomatic routes remained open between the Archduke of Austria and his wife Infanta Isabella (Philip's sister) who differed in their policies to Philip's. Philip wanted to preserve the hegemony of the Spanish empire, whilst the Archduke and Isabella sought peace and friendly relations. Soon after victory in Ireland the following year, the English navy under Richard Leveson conducted a blockade of Spain, the first of its kind. Off Portugal, they sailed into Sesimbra bay where a fleet of eight Spanish galleys under Federico Spinola (brother of Ambrogio) and Álvaro de Bazán were present. Spinola had already established his base at Sluis in Flanders and was gathering more with an intent on a potential strike against England. In June 1602 Leveson defeated the Spanish which resulted in two galleys sunk and the capture of a rich Portuguese carrack. Months later in the English channel Spinola's fleet gathered more galleys and sailed through the English channel once more but was defeated again by an Anglo-Dutch naval squadron off the Dover straits. Spinola's remaining galleys eventually reached Sluis. The result of this action forced the Spanish to cease further naval operations against England for the remainder of the war. After the death of Elizabeth I, however, Spain's priority was no longer an invasion of England, but the fall of Ostend. Treaty and aftermath The treaty restored the status quo ante bellum; the terms were favourable both to Spain and England. For Spain the treaty secured her position as a leading power in the world. Spain's upgrading of the convoy system had allowed it to defend its treasure fleets and retain its New World colonies. English support for the Dutch rebellion against the Spanish king, the original cause of the war, ceased. The Spanish could then concentrate their efforts on the Dutch, in the hopes of bringing them to their knees. A complete abandonment of the Dutch cause, however, was not promised in the treaty. The English-held cautionary towns in Holland on the other hand were not surrendered despite Spanish demands. The sieges of Ostend and Sluis were allowed to continue until the end