The term referred to the ‘first ten’ in a row (Greek δεκάπρωτοι, dekáprōtoi).
[1] The ten highest-ranking decuriones in the curia of a city
Decemprimi was the name for the ten highest-ranking decuriones in the curia of a city with a constitution based on Roman or peregrine law. They handled various tasks; in particular, they were prominent in legations (Liv. 29,15,5; Cic. Verr. 2,2,162). In the Roman Imperial period, the decemprimi gradually…