Definition
Apportionment of common is the legal doctrine by which a right of common — most typically common of pasture — is divided proportionally when the dominant tenement to which it is appurtenant is severed or partially alienated. When the owner of land to which a common right attaches transfers a portion of that land to another person, the common right does not disappear, nor does it remain wholly with the original owner. Instead, it splits: each parcel receives a share of the common right proportionate to its size or its capacity to support commonable animals. The transferee acquires common pro tanto — for so much — corresponding to the land received.
The doctrine rests on the principle that a right of common is an incorporeal hereditament running with the dominant land. Because it is incident to the land rather than personal to the owner, any division of the land necessarily carries a corresponding division of the appurtenant right.
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Common Confusion
Apportionment of common should not be confused with extinguishment of common. Extinguishment occurs when the right of common is permanently destroyed, typically by unity of seisin — that is, when the same person comes to own both the dominant tenement and the servient land over which the common is exercised. Apportionment, by contrast, preserves the right in divided form; no part of the common is lost, it is merely reallocated across the newly separated parcels. Researchers encountering historical disputes about whether partial alienation destroyed or merely divided a common right should look carefully at this distinction, as courts historically treated the two outcomes as turning on different facts and different remedies.
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Core Elements
The doctrine as it operated at common law required the following conditions:
1. A valid right of common appurtenant. The common right must be attached to a specific dominant tenement, not held in gross (personally, without reference to land). Common in gross was not subject to apportionment in the same manner because there was no land division to trigger the pro tanto division.
2. Severance of the dominant tenement. The owner of the dominant land must have aliened a portion — not the whole — of the land to a third party. A conveyance of the entire parcel transfers the common right intact; apportionment is only triggered when a part is carved out.
3. Proportional allocation. The share of common passing to the alienee corresponds to the portion of the dominant tenement conveyed. In the classic pasture context, the measure is the number of commonable cattle levant and couchant on the alienated portion — that is, the animals that lie down and rise on that land, a traditional measure of the land's carrying capacity.
4. No destruction of the right in the grantor. The grantor retains the residual common right over the remaining land. Neither party suffers a forfeiture.
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Why It Matters in Research
This term belongs to a cluster of common law property doctrines governing rights of common — pasture, estovers, piscary, turbary — that were fully operational in English law through the eighteenth century and carried into early American land law, particularly in New England and Mid-Atlantic jurisdictions where common field and pasture arrangements persisted after colonization. Researchers working with colonial-era deeds, manorial records, or early nineteenth-century American conveyancing treatises will encounter apportionment questions in disputes over divided town commons and shared grazing lands.
Two research traps are worth flagging. First, the vocabulary shifts: older sources use "common appurtenant," "common appendant," and "common in gross" as distinct categories with different rules, and apportionment applies most cleanly to the appurtenant variety. Conflating these categories will produce incorrect results when tracing a specific right through historical conveyances. Second, the levant-and-couchant test for measuring the apportioned share is a common law artifact that American jurisdictions progressively abandoned or codified away; researchers should not assume it governs in any modern American context without checking applicable state law.
The doctrine also has a theoretical connection to equitable apportionment principles more broadly, but that connection is terminological rather than substantive. Equitable apportionment of water rights (interstate or otherwise) operates on entirely different legal foundations.
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Historical Dictionary Support
Burrill's Law Dictionary provides the essential statement of the doctrine and is consistent with the classical common law authorities on which it relies. Burrill cites Coke's Reports (8 Co. 78b; 4 Co. 37) and Stephens's Commentaries (2 Steph. Com. 30) — standard primary and secondary sources for this area of English real property law. The entry is terse but accurate for its period: it identifies the triggering event (division of the dominant land), the operative measure (levant and couchant), and the pro tanto outcome.
What Burrill does not address is the American reception of the doctrine, which was uneven. Early American treatise writers, including Kent and Story, largely carried the English framework forward, but the practical significance of common rights declined sharply as common field systems dissolved and fee simple ownership of enclosed parcels became the norm. By the late nineteenth century, apportionment of common had become largely a historical topic in American legal writing, though it retained relevance in jurisdictions with active disputes over colonial-era commons or surviving town meeting lands.
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Jurisdictional Note
The doctrine is English common law in origin and has the most continued relevance in New England states, where town commons and historically shared grazing arrangements produced litigation well into the nineteenth century. Massachusetts and Connecticut courts applied the common law framework most fully. In most American jurisdictions today, surviving rights of common are rare, and where they exist, state statutory frameworks for easements and appurtenant rights will govern their division on severance rather than the classical common law rule.
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Encyclopedia Cross-Reference
The Law Mind Property Law Encyclopedia, property_10: Concurrent Ownership — Tenancy in Common (for background on appurtenant rights and the division of property interests on severance of ownership).
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