(_e_) _Primer Seisin_, which is usually regarded as a separate incident, and figures as such in Blackstone’s list, is perhaps better understood, not as an incident at all, but rather as a special procedure—effective and summary—whereby the Crown could enforce the four incidents already described. It was an exclusive prerogative of the Crown, denied to mesne lords.[105] When a Crown tenant died, the King’s officers had the right to enter upon immediate possession, and to exclude the heir, who could not touch his father’s lands without specific permission from the Crown. He had first to prove his title by inquest, to give security for any balance of relief and other debts unpaid, and to perform homage.[106] It will be readily seen what a strong strategic position all this assured to the King in any disputes with the heir of a dead vassal. If the Exchequer had doubtful claims against the deceased, its officials could satisfy themselves before admitting the heir to possession. If the heir showed any tendency to evade payment of feudal incidents, the Crown could checkmate his moves. If the succession was disputed, the King might favour the claimant who pleased or paid him most; or, under colour of the dispute, refuse to disgorge the estate altogether—holding it in custody analogous to wardship, and meanwhile drawing the profits. If the son and heir happened to be from home when his father died, he would probably experience great difficulty, when he returned, in forcing the Crown to restore the estates. Such was the experience of William Fitz-Odo on returning from Scotland in 1201 to claim his father’s carucate of land in Bamborough.[107] Primer seisin was thus not so much a separate incident, as a right peculiar to the Crown to take summary measures for the satisfaction of all incidents or other claims against a deceased tenant or his heir. Magna Carta admitted this prerogative whilst guarding against its abuse.[108] ----- Footnote 105: The Bishop of Durham enjoyed it, so it seems to be stated in a charter extorted from him in 1303 by the men of his fief (see Lapsley, _Pal. of Durham_, p. 133). But this forms no real exception; since the Bishop, as an Earl Palatine, enjoyed exceptionally the _regalia_ of a king. Footnote 106: See Pollock and Maitland, I. 292. It appears from statute of Marlborough, c. 16, that _primer seisin_ extended over lands held by serjeanty as well as by knight’s service. Footnote 107: _Rotuli de oblatis_, p. 114. Footnote 108: