Calgacus

thumb|upright=1.3|19th-century print depicting Calgacus delivering his speech to the Caledonians. According to Tacitus, Calgacus (sometimes Calgacos or Galgacus) was a chieftain of the Caledonian Confederacy who fought the Roman army of Gnaeus Julius Agricola at the Battle of Mons Graupius in northern Scotland in AD 83 or 84. Some older scholarship has proposed a Brittonic derivation, *calg‑ac‑os, meaning 'possessing a blade' or 'swordsman', but this interpretation is highly speculative and not attested in contemporary sources. Several scholars have connected the name Calgacus with the Gaelic root , meaning "a prickle; the point of a weapon; anything pointed". Related forms recorded in Dwelly's Illustrated Gaelic–English Dictionary include ("prickly; armed with points; fierce"), (a spear, a point) and ("pointer-finger"), all belonging to the same semantic field of pointed or projecting objects. MacBain's Etymological Dictionary of the Gaelic Language also records / as meaning "awn, bristle; anything pointed; a sword". Whether the word is a name or a title is unknown.

==Biography== He was the first Caledonian to be recorded in history. The only historical source that features him is Tacitus' Agricola, which describes him as "the most distinguished for birth and valour among the chieftains". Tacitus wrote a speech which he attributed to Calgacus, saying that Calgacus gave it in advance of the Battle of Mons Graupius. The speech describes the exploitation of Britain by Rome and rouses his troops to fight.