When John became king, he granted three charters, ratifying the privileges of the capital in return for a _gersuma_ (or slump payment) of 3000 marks.[488] All the franchises specified in the old charter of Henry I. were now confirmed, with one exception: the liberty to appoint a justiciar of their own, now seen to be inconsistent with the Crown’s centralizing policy, was abandoned. None of these charters made mention of mayor or commune, but they confirmed some minor privileges gained in Richard’s reign.[489] ----- Footnote 488: Miss Bateson, _Engl. Hist. Rev._, XVII. 508. Footnote 489: _E.g._ the removal of obstacles to free navigation in Thames and Medway. Cf. _infra_, c. 33. A fourth charter, dated 20th March, 1201, was merely of temporary interest; but a fifth, granted on 9th May, 1215, little more than a month previous to Magna Carta, is of great importance, and represents the bait thrown by John to the citizens in the hope of gaining their support in this new crisis, as he had previously gained it in the crisis of 1191. The fifth charter not merely confirmed to the citizens in explicit terms the right already enjoyed by them of electing a mayor for life, but allowed them to elect a new one every year. Miss Norgate does not exaggerate, when she describes this concession as “the crowning privilege of a fully constituted municipality, the right to elect their own mayor every year.”[490] An annually elected magistrate would, undoubtedly, feel his dependence on the citizens more than one holding office for life; but it seems probable that the chief value of the grant lay in its confirmation by John as king, of the rights conceded by him fourteen years earlier as his brother’s unauthorised representative, and enjoyed meanwhile on an insecure tenure. The charter of May, 1215, by officially recognizing the mayor, placed the commune over which he presided on a legal footing. The revolutionary civic constitution, sworn to in 1191 was now confirmed. The citizens acted on the permission granted them of annually changing their chief magistrate: but in place of supporting the king who made the grant, they opened their gates to his enemies.[491] ----- Footnote 490: _John Lackland_, 228. Footnote 491: From this date the list of mayors shows frequent, sometimes annual, changes. Thus Serlo the mercer was Mayor in May, 1215, when London opened its gates to the insurgents, while William Hardell had succeeded him before 2nd June, 1216, when he headed the citizens who welcomed Louis to make London his headquarters. -----