The Holocene history of the Hamilton basin and development of the soil pattern are closely related. The basin was partly filled by the large alluvial fan of the Waikato River which partly buried a hilly, ash-covered landscape. The normal depositional pattern of fans is recognisable (apex of coarse sediments; middle part with ridges of coarse sediments and swales with fine sediments; toe of fine sediments) but has been modified by changing river courses during fan building. Each of these courses was flanked by levees which dammed valleys and embayments and blocked drainage to form lakes. The lakes were the sources of the present day peat bogs. The properties of the soils developed on the wide range of parent materials and landforms in the basin are summarised.