Why is the ninth month called September?
1610s, "counting of heads," from Late Latin capitationem (nominative capitatio), noun of action from past participle stem of a verb derived from caput "head" (see capitulum). Meaning "levying of a poll tax" is from 1640s.
major direct tax in France before the Revolution of 1789, first established in 1695 as a wartime measure. Originally, the capitation was to be paid by every subject, the amount varying according to class. For the purpose of the tax, French society was divided into 22 classes, ranging from members of the royal family who owed 2,000 livres (basic monetary unit of pre-Revolutionary France) to dayworkers who owed only one livre. The tax became permanent in the early 18th century, with apportionment by an intendant (royal agent) replacing the class system of payment. In practice the capitation was merely an addition to the taille, the long-existing royal tax, falling predominantly on the nonprivileged classes of the French people, who paid the bulk of the taxes. It was abolished with the Revolution