As governor, he completed the conquest of what is today Wales and northern England, and led his army to the far north of Scotland, establishing forts across much of the lowlands.

He began his career in Roman public life as a military tribune, and served in Britain under Gaius Suetonius Paulinus from 58 to 62.

He was probably attached to the Legio II Augusta, but was chosen to serve on Suetonius's staff[4] and thus almost certainly participated in the suppression of Boudica's uprising in 61.

He was tribune of the plebs in 66 and praetor in June 68, during which time he was ordered by the Governor of Spain Galba to take an inventory of the temple treasures.

In 71, Bolanus was replaced by a more aggressive governor, Quintus Petillius Cerialis, and Agricola was able to display his talents as a commander in campaigns against the Brigantes in northern England.

The following year, Tacitus and Julia married; Agricola was appointed to the College of Pontiffs, and returned to Britain for a third time, as its governor (Legatus Augusti pro praetore).

Arriving in midsummer of 77, Agricola discovered that the Ordovices of north Wales had virtually destroyed the Roman cavalry stationed in their territory.

Almost two decades earlier, Governor Gaius Suetonius Paulinus had attempted the same but Roman forces had to withdraw in 60 CE because of the outbreak of the Boudican rebellion.

In the summer of 79, he pushed his armies to the estuary of the river Taus, usually interpreted as the Firth of Tay, virtually unchallenged, and established some forts.

[8] The text of the Agricola has been amended here to record the Romans "crossing into trackless wastes", referring to the wilds of the Galloway peninsula.

[9] Agricola fortified the coast facing Ireland, and Tacitus recalls that his father-in-law often claimed the island could be conquered with a single legion and auxiliaries.

This conquest never happened, but some historians believe the crossing referred to was in fact a small-scale exploratory or punitive expedition to Ireland,[10] though no Roman camps have been identified to confirm such a suggestion.

Tuathal Teachtmhar, a legendary High King, is said to have been exiled from Ireland as a boy, and to have returned from Britain at the head of an army to claim the throne.

[14] Agricola put his auxiliaries in the front line, keeping the legions in reserve, and relied on close-quarters fighting to make the Caledonians' unpointed slashing swords useless as they were unable to swing them properly or utilise thrusting attacks.

[15] Even though the Caledonians were put to rout and therefore lost this battle, two thirds of their army managed to escape and hide in the Highlands or the "trackless wilds" as Tacitus calls them.

He may have marched his army to the northern coast of Britain,[20] as evidenced by the probable discovery of a Roman fort at Cawdor (near Inverness).

[21] He also instructed the prefect of the fleet to sail around the north coast, confirming (allegedly for the first time) that Britain was in fact an island.