Just as in the 14th century the subsidy had followed the "old" and "new" customs, so in the 16th the "impositions" levied by royal prerogative formed a supplement to the parliamentary subsidy; but the principal employment of this expedient occurs in the next century. Another significant indication of the future course of indirect taxation was furnished by the grants of monopolies to inventors, producers and traders. These privileges, when they affected important commodities, operated in the same way as taxes farmed out to collectors, and, though the profit to the crown was small, they enhanced prices and excited discontent. The wisdom of Elizabeth (or her ministers) was shown in the promise of redress after the hostile debate of 1601. From one point of view it may fairly be said that the great struggle of the Stuart kings with the parliament centred round financial issues. It is, at all events, beyond dispute that questions of taxation were the chosen ground of conflict. Taking the period from the accession of James I. to the opening of the Civil War (1603-42) it appears that the legal basis of indirect taxation was tested for the port duties in the "Great Case of Impositions" (known as Bates' case, see BATES, JOHN), while that of direct taxation was considered in the even more famous "Ship Money" case (for ever associated with the name of Hampden). In parliament the debates deal with impositions, monopolies, the grounds for voting subsidies, and the proper application of the funds granted; in fact, with nearly all the financial questions of the time. Notwithstanding these difficulties and disputes the financial system shows evident signs of expansion and adaptation to the needs of the state.