Theses praediorum militarium 100

73. A plaintiff alleging investiture and claiming that vacant possession ought to be delivered to him by the Lord is bound to prove the investiture through co-vassals or a public instrument.

74. If he fails to prove it, the Lord must defend himself with twelve compurgators, [swearing] that he did not grant the investiture, or he must refer the oath.

75. Conversely, where the defendant alleges investiture and possesses the fief, the burden of proof rests upon the Lord claiming his property to show that he did not grant it by right of a proper fief.

76. If the Lord does not prove this, the defendant must swear with twelve compurgators that he was invested with that fief, and he shall retain possession.

77. If the defendant does not so swear, possession is to be restored to the Lord upon his taking the oath.

78. But if the defendant has possessed the fief during the preceding year, while the Lord was not ignorant of it and remained silent, he ought to swear alone and retain possession.

79. If, however, the Lord proves that he granted the estate by right of gastaldy or as a pledge, he is to be preferred to the defendant without the taking of an oath.

80. Nevertheless, a defendant who proves to the contrary, either through co-vassals or a public instrument, that the investiture was subsequent to the gastaldy or pledge, is preferred to the Lord.

81. Likewise, the defense rests upon one alleging succession to a fief and possessing it, but the proof rests upon the Lord who denies it; if the Lord proves his case, the former is defeated; if he does not prove it, the latter shall be overcome upon the taking of the oath [by the possessor].

82. But the burden of proof rests upon one alleging succession but not possessing it, and the defense upon the Lord who is in possession; and the former obtains [the fief] if he proves the succession, otherwise not.

83. A fief cannot be taken away from a vassal without a cause having been heard, and a fault convicted and approved by the judgment of peers.

84. Yet a lesser vassal may, whenever he pleases, take back what he gave as a fief to a valvassor.

85. All the causes for taking away a fief cannot be enclosed within a fixed definition.

86. And those which are causes for disinheritance, for revoking a gift, and for dissolving a marriage, are also to be observed in the revocation of a fief.

87. Therefore, the causes for removing and dispossessing a vassal are left to be debated by the judgment of peers, since they are discretionary, not fixed, nor defined by statute.

88. And the Lord is compelled to prove these causes to the peers of the court as witnesses.