Meanwhile the defenders of Ostend had been making a desperate resistance, and little progress was made by the besiegers, with the result that a great drain was made upon the finances of the archdukes and there were threatenings of mutiny among the troops.  But the situation was saved by the intervention of a wealthy Genoese banker, Ambrosio de Spinola, who offered his services and his money to the archdukes and promised that if he, though inexperienced in warfare, were given the command, he would take Ostend.  He fulfilled his promise.  Without regard to loss of life he pressed on the siege, and though as fast as one line of defences was taken another arose behind it to bar his progress, little by little he advanced and bit by bit the area held by the garrison grew less.  At last in the spring of 1604, under the pressure of the States-General, Maurice led an army of 11,000 men into Flanders in April, 1604, and laid siege to Sluis on May 19.  Both Maurice and William Lewis were still unwilling to run the risk of an attack on Spinola’s army in its lines, and so the two sieges went on side by side, as it were independently.  Sluis fell at the end of August, and Ostend was then at its last gasp.  Urged now by the deputies of the States to make a direct effort to relieve the heroic garrison, Maurice and his cousin, after wasting some precious time in protesting against the step, began to march southward.  It was too late.  What was left of Ostend surrendered on September 20, and Spinola became the master of a heap of ruins.  It is said that this three years’ siege cost the Spaniards 80,000 lives, to say nothing of the outlay of vast expenditure.  Whether Maurice and William Lewis were right or wrong in their reluctance to assail Spinola’s entrenched camp, it is certain that they were better judges of the military situation than the civilian deputies of the States.  In any case the capture of Sluis was an offset to the loss of Ostend; and its importance was marked by the appointment of Frederick Henry, the young brother of the stadholder, as governor of the seaport and the surrounding district, which received the name of States-Flanders.  The tremendous exertions put forward for the defence of Ostend had been a very serious drain upon the resources of the United Provinces, especially upon those of Holland.  Taxation was already So high that Oldenbarneveldt and many other leading members of the States-General and Provincial Estates began to feel despondent and to doubt whether it were possible to continue the war.  No longer could the States rely upon the assistance of England.  James I had concluded peace with Spain; and, though he made professions of friendship and goodwill to the Dutch, wary statesmen, like the Advocate, did not trust him, and were afraid lest he should be tempted to deliver up the cautionary towns into the hands of the enemy.  Reverting to the policy of William the Silent, Oldenbarneveldt even went so far as to make tentative approaches to Henry