Year 84 (LXXXIV) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar. Events By Place Roman Empire Possible date of the Battle of Mons Graupius (83 or 84), in which Gnaeus Julius Agricola defeats the Caledonians. Pliny the Younger's sevir equitum Romanorum (commander of a cavalry squadron). The construction of the Limes, a line of Roman fortifications from the Rhine to the Danube,'s begun. Through his election as consul for ten years and censor… (More on 84)