Mercia had collapsed by 874 and the Army's cohesion went with it. Halfdan went back to Northumbria and fought the Picts and the Strathclyde Welsh to secure his northern kingdom. His army settled there, and he is not mentioned after 876, when "Danes were engaged in ploughing and making a living for themselves". Guthrum, with two other unnamed kings, "departed for Cambridge in East Anglia". He made several attacks on Wessex, starting in 875, and in the last nearly captured Alfred in his winter fortress at Chippenham.