This quote does not correspond to a proclamation of the War of Independence against the Napoleonic troops nor to the work of an author of the extreme left, nor to an American indigenist speech against the Spanish conquest or one against the British Empire from one of its colonies. Tacitus wrote it almost two thousand years ago, in his Life of Julius Agricola (De vita et moribus Iulii Agricolae ), putting it in the mouth of Calgaco, the head of the rebellion of the Caledonian Confederation that faced the legions of Gnaeus Julius Agricola in defense of his land against the predatory desire of Rome.
Gnaeus Julius Agricola was born in AD 40. at Forum Julii, a Roman colony in Gaul Narbonensis where his father, Julius Grecinus, was praetor. Belonging to the senatorial class, Grecinus died by order of Caligula after refusing to obey his order to falsely accuse Marcus Junius Silanus (the emperor's father-in-law), an attitude that Caligula himself admired to the point that it justified his death « for being a better citizen than a tyrant can be" . This extraordinary demonstration of the Roman virtus provoked the admiration of Seneca and other moralists of the time, which Grecino would have liked because he himself was very fond of philosophy.
In fact, he tried to instill his study in his son, who grew up in Massilia (Marseille) before he began his cursus honorum as a military tribune in Britain, under the orders of Governor Gaius Suetonius Paulinus, probably participating in the repression of the insurrection of Queen Boudica in 61. The following year he returned to Rome to marry Domicia Decidiana, with whom he had a daughter, Julia Agricola, and a son who died prematurely. Agricola was later quaestor, tribune of the plebs and praetor, while Rome was involved in the instability brought about by the succession of Nero, when Galba, Otho, Vitellius and, finally, Vespasian alternated in power.
Under the latter, whom he had supported because his mother was killed by Ottonian troops, he was posted back to Britain as legate of the XX Legio Valeria Victrix , while at the same time Governor Marco Vecio Bolano, whose clumsy policy had provoked a rebellion, was replaced by Quinto Petilio Cerial. Agricola's effectiveness in defeating the northern tribe of the Brigantes earned him the rule of Gaul Aquitaine, before being recalled to Rome for his appointment as suffect (interim) consul. 
Those years were happy, because it was then that he acceded to the patriciate, promised his daughter to Tacitus (it is understood that the famous Roman historian became his biographer with the aforementioned De vita et moribus Iulii Agricolae , that is, Life and customs of Julio Agricola ), he entered the College of Pontiffs and returned to Britain as legatus Augusti pro praetore i.e. governor general. He surely did not imagine that he would remain there for the next seven years of his life to dominate the entire island territory.
The first stage of his rule, beginning in 77 AD, was peaceful. Showing great diplomatic skill, he placated the Britons by spreading among them the virtues of the Roman way of life, improving the urban planning of their cities, educating the sons of the nobility as his own - they even wore toga - and cleaning up the corrupt grain distribution system. In this way, control was extended to the Ordovics and Catfish of Wales and the North of England, leaving everything ready in a biennium to undertake the conquest of the always hostile Caledonia (Scotland), where the Picts, as the Romans called the natural, continued to resist Romanization.
It was not easy and he needed to develop up to five successive campaigns in as many years, between 80 and 84 AD. The last one was the most difficult because a charismatic leader emerged capable of uniting all the tribes under his command. His name was Calgaco and we hardly know anything about him, even though he is the first Caledonian to appear in recorded history with his own name. It is almost ironic that he owes this primal honor to his enemy's son-in-law, since it is Tacitus who has left evidence of him -certainly with first-hand information from his father-in-law-, describing him as "the most distinguished among the chiefs by birth and courage» .
The Caledonian southern section, between the Solway and Forth fjords, was less complicated to pacify and served as a base of operations to face the more complicated part, the northern one, where in 83 AD. a surprise night attack by the enemy on the IX Legion camp nearly ended in disaster. The Romans managed to pull themselves together and push him back, only to enter hostile territory the following year. Vacomages, Texalians, Venicons and other Pictish peoples grouped in a confederation and reinforced with British fugitives, of whom there were also auxiliaries in the legions, were waiting there to try to compensate for the numerical difference.
And it is that Calgaco managed to set up an imposing army that, according to Tacitus, would be around thirty thousand men, while Agricola had a similar number or somewhat less, four thousand legionnaires of the aforementioned IX (La II Augusta was left in Wales) plus the addition of eight thousand infantry and four alae auxiliary cavalry. In reality, as usual, it is impossible to know the exact figures, especially having a single source, and there would probably be fewer Picts; After all, the work of Tacitus is hagiographic.
In any case, Agricola advanced from Camelon to the River Tay, in Perth, where Calgaco awaited him, taking advantage of the orographic advantage provided by the Grampian mountains. It is a mountain chain that occupies the central area of the Highlands (hence its name), with its maximum height of 1,343 meters. The reason for its etymology is unknown, the traditional version that the Erasmian historian Héctor Boece gave in 1527 in his Historia Gentis Scotorum being discarded by experts. (History of Scotland ), identifying the exact point of the battle on a Mount Graupius that has never been located (nor is that word of Celtic origin).
The clash was inevitable because the Caledonians, aware of Roman tactical superiority, had so far avoided engaging them in the open. But now they found that the cunning adversary forced the defeated peoples to supply them, while destroying the crops of the others, which meant starving before the arrival of the next winter; therefore, put to death it was preferable to do it fighting. And that is where Tacitus includes Calgaco's emotional speech, imitated a thousand times in the cinema.
The harangue had an effect and was acclaimed with vibrant chants that Agricola deemed it convenient to counteract by encouraging his own.
That magnificent oratorical duel did not take long to materialize in battle. The legionnaires, fired up, fell into battle formation behind a line of trenches, protecting their castrum and in reserve functions, since Agricola aspired to obtain victory without suffering a single Roman casualty. So he placed the Germanic auxiliary veterans (three cohorts of Batavians and two of Tungros) in the center and the cavalry on the wings, as was customary; They formed a long line to prevent the Caledonian chariots from encircling them, and the legate himself left his horse to take the lead on foot. He then ordered a charge that pushed the Picts up the slope, as their long swords prevented them from fighting in close formation.
When the British auxiliaries joined this penetration into the mass of Caledonian warriors, they were thrown into chaos, mixing the living with the dead, infantry with horsemen, men with runaway horses. Calgaco sent his reserve cavalry but collided with the Roman and was disrupted. The Pictish ranks were definitely broken, and while some fled for the safety of a nearby forest, others stayed put, ready to hold out to the end. And it came to them, of course, since it was a resounding Roman victory; according to Tacitus, the enemy had ten thousand dead for only three and a half hundred of his own auxiliaries.
Agricola won a triumph and a statue in Rome, where Domitian already reigned. It is said that the latter, jealous of the legacy's popularity, replaced him in Britain with Sallust Lucullus. In any case, military needs in other corners of the empire forced the withdrawal of troops from the island, giving a respite to the Caledonians, who had been so up to their necks in water that, on the night of defeat, some even killed their families to prevent them from being taken prisoner. That missed opportunity was bitterly described by Tacitus with the expression «Perdomita Britannia et statim missa » (Britain was completely conquered and immediately abandoned.)
Assuming all of this is true, of course. Leaving a newly taken place to establish a limes much further south has led some historians to suggest that the battle of Mons Grapius either it wasn't that important or it didn't even really happen. Something that would reinforce the fact that only the son-in-law of its protagonist reviews it; the antagonist, Calgaco, was never even mentioned again, so we don't know what became of him.