Siege of Flevum: unsuccessful Frisian attack on a Roman fort in 28 CE, probably identical to Velsen.
In 28, the Frisians, a Germanic tribe living in what is now called Holland and was then known as Germania Inferior, revolted against the Romans. Although the rebels were defeated, the Roman emperor Tiberius gave up the occupation of Frisia. Almost a century later, the story was told by the Roman author Tacitus (Annals, 4.72-73). His account is offered here in the translation by A.J. Church and W.J. Brodribb.
[4.72] That same year [28 CE] the Frisians, a nation beyond the Rhine, cast off peace, more because of our rapacity than from their impatience of subjection.
Drususnote 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 Frisians, 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.
[4.73] As soon as this was known to Lucius Apronius, propraetor of Germania Inferior, 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 Frisians, raising at once the siege of the fortress and dispersing the rebels in defense of their own possessions.
Next, he began constructing solid roads and bridges over the neighboring estuaries for the passage of his heavy troops, and meanwhile having found a ford, he ordered the cavalry of the Cananefates, with all the Germanic 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 Braduhenna'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.
[4.74] The Frisian name thus became famous in Germany, and [the emperor] Tiberius kept our losses a secret, not wishing to entrust any one with the war. Nor did the Senate care whether dishonor fell on the extreme frontiers of the empire.