Estate and manorial records are held in great profusion, having been deposited by the owners of major estates, solicitors and private individuals. Those of most value are deeds, manor court rolls, surveys, rentals and leases. Particularly popular in Somerset from the early 16th century were leases for 99 years or three lives. As these lives were often members of the lessee's family (relationships being stated and, from the early 18th century, ages often being given) such documents can establish a descent even when the parish registers are deficient or missing. Sequences of deeds and manor court rolls, the latter usually in Latin before 1733, can also serve the same purpose. The Place Name and Manorial indexes in the searchroom provide details of surviving estate and manorial records. When trying to trace an ancestor's house or property, estate, enclosure and tithe maps will be of use. Comprehensive map catalogues are available. For many parishes, however, there will be no detailed map earlier than the tithe map (c. 1840). For other classes of document consult the general Place Name Index and then find fuller details from the office catalogues. The index is in no way comprehensive.