The court found that the Siaya Land Tribunal lacked jurisdiction to entertain disputes relating to registered land parcels, as its statutory mandate under Section 3(1) of the Land Disputes Tribunal Act is limited to matters involving division, boundaries, occupation, or trespass to land held in common. The applicant, though not the registered proprietor, was properly before the court as he was joined in the tribunal proceedings by the interested party and recognized as the heir to the estate. The tribunal's decision to order cancellation of title deeds and subdivision of registered land was ultra vires and thus null and void. The court emphasized that jurisdiction cannot be conferred by consent or estoppel, and any decision made without jurisdiction is a nullity. Accordingly, the orders of certiorari were granted to quash the tribunal's decision and the consequential award by the Principal Magistrate's Court.