_Supra_, p. 303, and cf. Pollock and Maitland, I. 331. Footnote 529: See Madox, I. 677. The first Statute of Westminster virtually reverted to the rule laid down in 1215, for its terms imply that aids could only be taken on the three well-known occasions. The vague declaration that these should be reasonable in amount is replaced by the specification of a fixed rate, namely 40s., or double what had been usual at an earlier period. Definition of the amount and times of payment may, however, have been worth purchasing even at this increase. ----- CHAPTER SIXTEEN. Nullus distringatur ad faciendum majus servicium de feodo militis, nec de alio libero tenemento, quam inde debetur. No one shall be compelled to perform greater service for a knight’s fee, or for any other free tenement, than is due therefrom. For military tenants, the transition from scutage to service was a natural one; since it was not enough to protect themselves from exactions in money, if they were still exposed to arbitrary exactions in kind. John, therefore, declared that no freeholder should be constrained to do more service for his lands than he was legally bound to do. Disputes might arise, however, as to what extent of service actually was due in each particular case, and Magna Carta did nothing to remove such ambiguities. The difficulties of definition, indeed, were enormous, since the duration and conditions of service might vary widely even among tenants-in-chivalry, in consequence of special exemptions or special burdens which appeared in title deeds or rested upon immemorial usage. The barons would be unwilling to enter on so intricate and laborious a task, fearing that the introduction of such complications might do more harm than good. The necessity for accurate definition may never have occurred to them: the main purport of their grievance was so vividly present to their own minds that they did not acknowledge the possibility of any mistake. The military Crown tenants had frequently objected to serve abroad, particularly during John’s campaigns in Poitou, which involved a long expensive journey to a region in which they had nothing at stake.[530] They regarded themselves as not legally bound to make expeditions to such portions of the Angevin Empire as had not belonged to the Norman kings when their ancestors got their fiefs. To force them to enter on campaigns to the south of France, or to fine them heavily for staying at home, was, they argued, to distrain them _ad faciendum majus servicium de feodo militis quam inde debetur_. When they inserted these words in the Charter, they doubtless regarded them as an absolute prohibition of compulsory service in Poitou, at all events.[531] The clause was wide enough, however, to include many minor grievances connected with service. The barons did not confine its provisions to military service even, but extended it to other forms of