The Eastern Association has an assured place in any history of the Civil War. Within the region, early in 1643, Oliver Cromwell and his 'Iron-sides' first rose to prominence; in 1644 the seven constituent countries raised the force which, at Marston Moor, tipped the military balance decisively against the king, and was to become the major component in the New Model Army in 1645. Using a wide selection of original national and local archival materials, Dr Holmes seeks to provide an explanation of the impressive performance of the Association in the war. He emphasizes the need to combine studies which have too often been regarded as autonomous fields of enquiry - of military organization, of central politics, of the local communities - to obtain a total perspective.