Baduhenna Lore from The Annals, Book IV (23-28 C.E.) by the Roman historian Tactitus translated by Alfred John Church and William Jackson Brodribb
That same year the Frisii, a nation beyond the Rhine, cast off peace, more because of our rapacity than from their impatience of subjection. Drusus had imposed on them a moderate tribute, suitable to their limited resources, the furnishing of ox hides for military purposes. No one ever severely scrutinized the size or thickness till Olennius, a first-rank centurion, appointed to govern the Frisii, selected hides of wild bulls as the standard according to which they were to be supplied. This would have been hard for any nation, and it was the less tolerable to the Germans, whose forests abound in huge beasts, while their home cattle are undersized. First it was their herds, next their lands, last, the persons of their wives and children, which they gave up to bondage. Then came angry remonstrances, and when they received no relief, they sought a remedy in war. The soldiers appointed to collect the tribute were seized and gibbeted. Olennius anticipated their fury by flight, and found refuge in a fortress, named Flevum, where a by no means contemptible force of Romans and allies kept guard over the shores of the ocean.
As soon as this was known to Lucius Apronius, propraetor of Lower Germany, he summoned from the Upper province the legionary veterans, as well as some picked auxiliary infantry and cavalry. Instantly conveying both armies down the Rhine, he threw them on the Frisii, raising at once the siege of the fortress and dispersing the rebels in defence of their own possessions. Next, he began constructing solid roads and bridges over the neighbouring estuaries for the passage of his heavy troops, and meanwhile having found a ford, he ordered the cavalry of the Canninefates, with all the German infantry which served with us, to take the enemy in the rear. Already in battle array, they were beating back our auxiliary horse as well as that of the legions sent to support them, when three light cohorts, then two more, and after a while the entire cavalry were sent to the attack. They were strong enough, had they charged altogether, but coming up, as they did, at intervals, they did not give fresh courage to the repulsed troops and were themselves carried away in the panic of the fugitives. Apronius entrusted the rest of the auxiliaries to Cethegus Labeo, the commander of the fifth legion, but he too, finding his men's position critical and being in extreme peril, sent messages imploring the whole strength of the legions. The soldiers of the fifth sprang forward, drove back the enemy in a fierce encounter, and saved our cohorts and cavalry, who were exhausted by their wounds. But the Roman general did not attempt vengeance or even bury the dead, although many tribunes, prefects, and first-rank centurions had fallen. Soon afterwards it was ascertained from deserters that nine hundred Romans had been cut to pieces in a wood called Baduhenna's, after prolonging the fight to the next day, and that another body of four hundred, which had taken possession of the house of one Cruptorix, once a soldier in our pay, fearing betrayal, had perished by mutual slaughter.