Obv. IMP TRAIANO AVG GER DAC PM TR P COS V PP. Laureate head right; Rev. SPQR OPTIMO PRINCIPI. Dacian wearing peaked cap, seated on shield in mourning, with sword below. Reference: RIC II 219, BMC 175, RSC 529. The legend on the obverse abbreviates Imperator. Trajan. Augustus. Germanicus. Dacius. Pontifex Maximus. Tribuniciae Potestate. Consul V. Pater Patriae, and the reverse, Senatus Populus Que Romanus. Optimo Principi is not abbreviated but spelled out in full. Trajan was notorious for the length of his numismatic inscriptions, which are the longest of any emperor. Here, the titles actually continue onto the reverse of the coin. They all translate as "Imperator, Trajan the Augustus, victor over the Germans and Dacians, chief priest, with the power of a tribune, consul for the fifth time, father of his country, the Senate and People of Rome: best of emperors."
Such a lengthy inscription allows the coin to be dated with considerable accuracy. Of course, it must date after AD 98, when Trajan began his reign and he received the titles of Augustus, Pontifex Maximus, and Pater Patriae. And it is later than AD 102, when he was hailed as Dacius, or AD 103, when such coins began to be struck in the dedicatory dative instead of the nominative—TRAIANO instead of TRAIAN(US)—and Trajan was made consul for the fifth time (AD 103-111).
It is the image on the reverse, however, that allows the most precise date. In AD 107, coins such as this denarius were issued to celebrate the end of the Second Dacian War late the previous year. Indeed, Dacia was so thoroughly Romanized after its conquest that it now is known as Romania, its language the only one in the Balkans to be derived from Latin.
The sword below the Dacian warrior is not broken but a falx, a curved sword shaped like an elongated sickle.