The Anglo-Saxon dagger you're describing is a significant archaeological find from the 7th or 8th century AD. It was discovered in an Anglo-Saxon grave during an excavation led by local archaeologist W. J. Andrew at Oliver's Battery, near Winchester, in 1930.
This dagger, more accurately referred to in Anglo-Saxon studies as a "syx" or long knife, likely had multiple purposes, with fighting and hunting being among the potential uses. These types of objects were commonly included as grave goods in Anglo-Saxon burials during the seventh and eighth centuries, and they sometimes featured elaborate decoration. The specimen you mentioned is particularly notable for its silver footstool, which is in the shape of a hat. This level of craftsmanship suggests its high quality and possibly a special status or significance for its owner.
During the excavation, it was observed that the corrosion of the iron had preserved remnants of a wooden sheath, likely made from oak. Such findings provide valuable insights into the weaponry, craftsmanship, and burial practices of the Anglo-Saxon period, shedding light on the daily lives and customs of this historical era.