which properly means watchmen or
sentinels of any kind (Caes. Bell. Gall.
7.69), was the name
more particularly given to the soldiers of the cohort who guarded the palace
of the Roman emperor (Suet. Nero 8
6). Their commanding officer was called tribunus excubitor
9). When the emperor went
to an entertainment at the house of another person, the excubitores appear
to have accompanied him, and to have kept guard as in his own palace (Suet.