Buckinghamshire was assessed at a ship of four hundred and fifty tons, or a sum of four thousand five hundred pounds.  The share of the tax which fell to Hampden was very small; so small, indeed, that the sheriff was blamed for setting so wealthy a man at so low a rate.  But, though the sum demanded was a trifle, the principle involved was fearfully important.  Hampden, after consulting the most eminent constitutional lawyers of the time, refused to pay the few shillings at which he was assessed, and determined to incur all the certain expense, and the probable danger, of bringing to a solemn hearing, this great controversy between the people and the Crown.  “Till this time,” says Clarendon, “he was rather of reputation in his own country than of public discourse or fame in the kingdom; but then he grew the argument of all tongues, every man inquiring who and what he was that durst, at his own charge, support the liberty and prosperity of the kingdom.”

Towards the close of the year 1636 this great cause came on in the Exchequer Chamber before all the judges of England.  The leading counsel against the writ was the celebrated Oliver St. John, a man whose temper was melancholy, whose manners were reserved, and who was as yet little known in Westminster Hall, but whose great talents had not escaped the penetrating eye of Hampden.  The Attorney-General and Solicitor-General appeared for the Crown.

The arguments of the counsel occupied many days; and the Exchequer Chamber took a considerable time for deliberation.  The opinion of the bench was divided.  So clearly was the law in favour of Hampden that, though the judges held their situations only during the royal pleasure, the majority against him was the least possible.  Five of the twelve pronounced in his favour.  The remaining seven gave their voices for the writ.

The only effect of this decision was to make the public indignation stronger and deeper.  “The judgment,” says Clarendon, “proved of more advantage and credit to the gentleman condemned than to the King’s service.”  The courage which Hampden had shown on this occasion, as the same historian tells us, “raised his reputation to a great height generally throughout the kingdom.”  Even courtiers and crown-lawyers spoke respectfully of him.  “His carriage,” says Clarendon, “throughout that agitation, was with that rare temper and modesty, that they who watched him narrowly to find some advantage against his person, to make him less resolute in his cause, were compelled to give him a just testimony.”  But his demeanour, though it impressed Lord Falkland with the deepest respect, though it drew forth the praises of Solicitor-General Herbert, only kindled into a fiercer flame the ever-burning hatred of Strafford.  That minister in his letters to Laud murmured against the lenity with which Hampden was treated.  “In good faith,” he wrote, “were such men rightly served, they should be whipped into their right wits.”  Again he says, “I still wish Mr. Hampden, and others to his likeness, were well whipped into their right senses.  And if the rod be so used that it smart not, I am the more sorry.”