Then one of their foraging parties arrived with the intelligence that a great Saxon army was upon them.

The Danes were seized with a sudden panic, and fled precipitately to their ships, leaving behind them the horses they had brought from France, their stores, and all the prisoners and spoil they had gathered in their incursions in the neighbourhood of Rochester.

Seeing how well the Saxons were prepared for resistance the greater portion of the Danes crossed to France, but sixteen of their vessels entered the Stour and joined their allies of East Anglia.
Alfred ordered his fleet to assemble in the Medway, and in a fortnight the vessels from all the southern ports arrived.

They were filled with fighting men, and sailed to attack the Danes in the Stour, after which the force was to land and to inflict a severe punishment upon East Anglia.

On hearing of the gathering of the Saxon fleet Athelstan sent across to France and begged the Danes to come to his assistance, but none of their vessels had arrived when the Saxon fleet reached the mouth of the Stour.
The fighting force on board the Danish ships had been largely reinforced by their countrymen of East Anglia, and in a close body they rowed out to give battle to the Saxons.