Vicennalia

Apart from the Vicennalia, 136 was an eventful year for the imperial family: the serious illness of Hadrian in the spring, the adoption of Aelius in the summer and the death and consecration of Sabina at the end of the year.

Source: wiktionary

The exact timing of the tenth and twentieth anniversaries, the decennalia and the vicennalia, has already been discussed at length. The most straightforward solution, that it took place on the emperor's dies imperii ten years after the accession, has its adherents. However, a date earlier in the year, perhaps even the day of the beginning of the tenth year, may also be considered—at least in the second century AD.

Source: wiktionary

As a chronological list of Roman emperors makes clear, several rulers reign long enough to enjoy their decennalia, but relatively few were fortunate enough to celebrate their vicennalia, their twentieth imperial anniversary; and from the second century onwards Constantine alone ruled long enough to celebrate a tricennalia.

Source: wiktionary

Apart from the Vicennalia, 136 was an eventful year for the imperial family: the serious illness of Hadrian in the spring, the adoption of Aelius in the summer and the death and consecration of Sabina at the end of the year.

Source: wiktionary