If a document refers to your ancestor as the lessor on lease–he owns the property that is the subject of the lease. If your ancestor is referred to as the lessee, he is the person being given temporary use of the property. The lessor owns it, the lessee borrows it–generally speaking.
Leases are not often recorded. If there was a disagreement about the interpretation of the lease or if the lessor or lessee refused to live up to their obligations under the lease, a court action may have been the result. In that case the lease may be contained in the court records.