<jats:p content-type="no-indent">Some languages use a special form of the noun, a “numerative”, after some or all numerals. In such languages, a distinct numerative is typically not available for all nouns, but rather only for a small subset, forming a morphological “minor category” (jats:xrefCorbett 2000</jats:xref>). We examine how such a system emerges and disintegrates diachronically, looking in detail at Welsh, a language in which a distinct numerative emerged as the result of the phonological attrition of plural suffixes and analogical extension of new plural suffixes to all relevant syntactic environments except after numerals. Nouns with distinct numeratives tend to be animate and to denote units frequently counted, an association previously noted also for minor duals (jats:xrefPlank 1996</jats:xref>). We suggest that this association arose in Welsh via differential analogical extension in two directions: animates resisted analogical extension of the pattern numeral + singular noun; and animates were most receptive to extension of the pattern numeral + numerative. We show that the loss of the numerative proceeded the same way in reverse: numeratives were first reanalyzed as special plurals, and this pattern, numeral + plural noun, resisted analogical spread of the dominant numeral + singular pattern most robustly with kinship terms and a unit of time, namely ‘year’. These developments show much commonality with other cases where the diachrony of the numerative is known, confirming the observation that numeratives typically emerge from the disintegration of a major category, such as plural or dual, and that they are diachronically unstable, liable ultimately to analogical elimination.</jats:p>