After the signing of the treaty with Guthrum, Alfred was spared any large-scale conflicts for some time. Despite this relative peace, the king was forced to deal with a number of Danish raids and incursions. Among these was a raid in Kent, an allied kingdom in South East England, during the year 885, which was possibly the largest raid since the battles with Guthrum. Asser's account of the raid places the Danish raiders at the Saxon city of Rochester, where they built a temporary fortress in order to besiege the city. In response to this incursion, Alfred led an Anglo-Saxon force against the Danes who, instead of engaging the army of Wessex, fled to their beached ships and sailed to another part of Britain. The retreating Danish force supposedly left Britain the following summer.