Start with the three map families that cover almost everywhere

Almost every parish in Britain has been surveyed, drawn and redrawn many times over the last three centuries, and the chances are good that a decent run of those maps survives for your own patch. The trick is knowing which to reach for first. Three families of document do most of the heavy lifting: tithe maps and their accompanying schedules, estate plans, and the great county series produced by the Ordnance Survey. Used together, they let you date a hedge, trace a footpath back past living memory, and pin down the exact spot where a cottage or a barn once stood.

Work from the known to the unknown. Begin with a modern map of the area, then step backwards through the editions, rather than trying to decode an eighteenth-century plan cold.

Tithe maps and apportionments: the 1840s baseline

The Tithe Commutation Act of 1836 replaced payments in kind with a cash rent charge, and to work out who owed what, most parishes were mapped afresh. The result is a large-scale plan of fields, lanes and buildings, usually drawn between the late 1830s and the 1850s, with a written apportionment schedule that acts as a key. Each field carries a number, and the schedule lists the landowner, the occupier, the field name, the acreage and the state of cultivation — arable, meadow, pasture or woodland.

Those field names are the most valuable thing in the whole document. Names like Kiln Field, Great Barn Close, Chapel Piece, Rye Croft or Marlpit Piece often preserve the memory of a use that had already vanished by the time the surveyor arrived. Keep an eye on the scale too: larger parishes were often mapped at about six chains to the inch, smaller ones at three, and the finer sheets show individual trees, gates and garden plots. Not every parish has one — some were covered only by a tithe agreement, and a few had commuted earlier — so check the catalogue before you assume a gap means nothing survives.

Estate plans: the landlord's eye on the landscape

Estate plans were commissioned by owners rather than by government, which makes them wonderfully detailed and slightly suspect in equal measure. They show parkland, carriage drives, lodges, ha-has, kitchen gardens, fishponds and model farmyards, and they frequently mark proposals that were never carried out. A plan can show a lodge that only ever existed as an architect's dotted outline.

Date them carefully. Look for the surveyor's name, the year, and any pencil annotations added later, which often record sales, felled timber or new tenancies. Where an estate plan overlaps a tithe map, you can sometimes watch a boundary being moved within a single decade.

Ordnance Survey: continuity you can compare

The county series is where old maps become genuinely forensic. The six-inch sheets, at roughly 1:10,560, give the broad picture, but the twenty-five-inch sheets at 1:2,500 are the ones to study for field boundaries, outbuildings and garden walls. Coverage began in the mid-nineteenth century and was revised every twenty to thirty years, so a run of three or four editions is usually enough to date a change to within a decade.

Read the small marks as carefully as the big ones. Bench marks, spot heights, parish boundary dots, and the abbreviations F.P. for footpath and B.R. for bridle road all carry meaning. Railway sidings, allotment grids and new cemeteries give you a reliable sense of which edition you are looking at even before you read the date.

What to look for once you have the sheets side by side

• Field boundaries: long, straight, ruler-straight hedges usually point to parliamentary enclosure; wavy, irregular lines tend to be older. A boundary present in 1840 and gone by 1900 tells you when a farm was amalgamated.
• Footpaths: paths shown on tithe maps may have had no legal status at all. The definitive legal record only arrives with the surveys that followed the National Parks and Access to the Countryside Act of 1949, so compare the two before assuming a right of way.
• Vanished buildings: look for small labelled rectangles — smithy, cottage and garden, parsonage, school. Where a building disappears between editions, note whether the site stays as an orchard, a pond or a patch of rough ground. That is often the trace you can still find on the ground.
• Water and industry: ponds, wells, pumps, quarries, limekilns, saw pits and decoy ponds are marked with real precision and are frequently the only surviving evidence of a trade.
• Ridge and furrow: sometimes shown by hachures or shading on early editions, and often still visible as earthworks under grass.

A workable routine for a Saturday afternoon

Order or download the sheets for your area at matching scales, print them at the same size, and lay them out in date order. Photograph the run so you can compare on a phone while standing in the field. Then walk the boundaries you have identified, checking for old hedge stools, stunted oaks on a ditch line, or a change in grass colour where a path once ran.

Take notes on site and add the date; memory fades faster than you expect. Ask your county record office about enclosure awards, which often include their own maps, and about any sale particulars, which sometimes carry plans more accurate than the estate version. Finally, treat every field as private land unless you know otherwise, and take nothing but photographs.