The bollock dagger or kidney dagger is a type of dagger with a distinctively shaped shaft, with two oval swellings at the guard resembling male genitalia ("bollocks"). The guard is often in one piece with the wooden grip, and reinforced on top with a shaped metal washer. The dagger was popular in Flanders, England and Scotland between the 13th and 18th centuries, and in particular the Tudor period. It was commonly carried by many Border Reivers, as a backup for the lance and the sword. A large number of such weapons were found aboard the wreck of the Mary Rose. In use, the bollock dagger was similar to the Scottish dirk.