May 1 – Emperor Diocletian abdicates at age 60 and retires to his palace at Salona (modern Split) on the Adriatic coast after a reign of nearly 21 years in which the last vestiges of republican government have disappeared.
The mausoleum was built like the rest of the palace with white local limestone and marble of high quality, most of which was from marble quarries on the island of Brač, with tuff taken from the nearby river Jadro beds, and with brick made in Salonitan and other factories.
The area is intimately associated with the heartland of the Delmatae and the area's strategic importance is emphasised by the citing of the legionary fortress at Tilurium (Gardun), just above today's city of Trilj, which guards the entrance to the valley from the south and the approach to the provincial capital at Salona.
The regiment's inscriptions have been found at the following Roman forts (in likely order of occupation): Humac; Burnum; Salona; Muć; Baratsföldpuszta (Pannonia).
Originally found in Salona, it is now kept in the Archaeological museum in Zagreb.
A further inscription (in Latin) discovered near Salona, Dalmatia, (now Split, Croatia) honouring the Emperor Marcus Aurelius Probus was dedicated by an "Aurelius Marcianus", a Vir Perfectissimus, described as Praeses, i.e. equestrian governor, of the province of Dalmatia.
Frederick sent Berenguer Estanyol d'Empúries to act as Manfred's vicar general and Deslaur stepped down from his post as leader of the Company and duke of Athens, retiring to his castle at Salona, which he either escheated, or he was forced to relinquish, to Alfonso Fadrique around 1320.
The third conflict occurred between 78 BC - 76 BC and finished with the capture of the Dalmatae stronghold, Salona (port Solin near modern city Split) by the proconsul C. Cosconius.
In the 7th century, following the fall of Salona, the capital of the Roman province of Dalmatia, many of its people sought refuge in Faria and other Roman towns in the nearby islands, as noted by the historian Archdeacon Thomas of Split (1200–1268) in his Historia Salonitana.
East of the center of McLean, SR 123 passes by the preserved Salona estate and close to Hickory Hill—a historic house on Chain Bridge Road that was home to Robert F. Kennedy—in Langley, where the state highway meets the eastern end of SR 193 (Old Georgetown Pike).