The other sources of the royal revenue, which at least in the beginning may be said to have accrued to the king by reason of personal obligation, were the military, the judicial, and the police powers. By reason of the military power vested in him, the king could demand the services of all freemen to fulfill the _trinoda necessitas_,--service in the militia, repair of bridges, and the maintenance of fortifications. Further, in accordance with the system of vassalage incident to his military power, he had the right of _heriot_,[3] according to which the armor of a deceased vassal became the property of the king. The judicial authority, also, was a fruitful source of income; from it the king adduced a right to property forfeited in consequence of treason, theft, or similar crimes, and to the fines which were payable upon every breach of the law. The third great power vested in the royal person was the police control; under it the king turned to account the privilege of market by reserving to himself certain payments; also the protection offered to Jews and merchants was paid for, and the king pocketed the bulk of the tribute. Beyond these,--and here we have the analogy of the later royal claim to purveyance,--the districts through which the king passed or those traversed by messengers upon the king’s business, lay under obligation to supply sustenance throughout the extent of the royal sojourn. [Danegeld, 991] It is apparent that an extraordinary occasion had to arise before this large ordinary revenue should prove to be inadequate to meet all reasonable royal necessities. The whole matter is shrouded in obscurity, yet it is unlikely that this extraordinary occasion arrived before the onslaught of the Danes. There is no record of an earlier instance.