Battle of The Sabis - Battle

Battle

Caesar's legions had been marching in Nervian territory for three days, following an ancient road. He learnt from prisoners that the Belgae were massing on the far side of the River Sabis, which was about ten miles ahead. The Nervii had persuaded the Atrebates and the Veromandui to support them. The Aduatuci were marching to join them, but they did not arrive in time to take part in the battle. Their non-combatants had moved to a safe area screened by marshes, where an army could not approach. The Belgae had made their preparations and were now waiting for the Romans.

Caesar sent forward experienced scouts to choose the next campsite.

He learnt from prisoners taken later that sympathisers in the ragtag of surrendered Belgae and other Gauls travelling with the army had gone to the Nervii and reported his disposition of his column. They reported that the individual legionary baggage trains were interspersed between the legions and that it would be easy to cut off the leading legion from the rest and destroy it before any support could reach it. It was believed this would intimidate the Romans into withdrawing. The Nervii, having traditionally always relied on infantry rather than cavalry had, over the years, developed a technique of building dense, impenetrable hedges of briars and thorns set between young trees as a defence against the raids of surrounding tribes. These would obstruct Caesar’s advance and help the attack. It was agreed that the signal for an attack was to be the appearance of the baggage train behind the first legion. In doing this, the Nervii were intending to use what is recognisable today as the modern army doctrine of force concentration. As will be seen, their plan would be frustrated by Caesar.

The campsite was to be laid out on a hill which gently sloped down to the river. On the other side of the river there was another hill directly opposite, similarly sloping. The top of that hill was densely wooded but the lower part was open and sloped down to the river over a distance of 200 paces (roughly 300 metres or 325 yards). The enemy was concealed inside the woods, but a few cavalry pickets could be seen in the open area by the river. The river was very wide but only about 3 feet (one metre) deep.

At some point on his march to the Sabis, Caesar reorganized the column and reverted to his usual tactic of leading his forces with six legions in light marching order. Behind them was the baggage column of the entire army, followed by the newly-recruited legions, XIII and XIV. Caesar does not say whether this change was fortuitous or was made in response to the intelligence received. While Caesar's force began to set up camp on the slope running down to the river, his cavalry, together with slingers and archers, was ordered to cross the river to reconnoitre. This developed into a skirmish with the few troops of Belgic cavalry that had been observed on the far side. Caesar describes the enemy cavalry as sallying repeatedly from the woods at the top of the hill and says his cavalry did not dare follow them in when they retreated. He does not elaborate further so it will never be known if the Nervii were trying to entice the skirmishers onto their hidden position or holding them in play on the slopes in preparation for the planned rush.

Meanwhile, the legions had started arriving at the camp site and began to build its fortifications. The Belgae, waiting for the baggage train to appear, gradually found themselves faced with not one legion, but six. Their plan of piecemeal destruction had to be abandoned, but they must have believed their numbers more than adequate to deal with their enemy.