There’s a Medieval European knife the Victorians called a Kidney Dagger. It had a long straight blade. The handle was a straight tube. The guard was two round lobes on either side of the grip. Victorian prudery aside, it was originally called a Bollocks Dagger. It’s supposed to be the ancestor of the Scottish Dirk.

Cocky young knights used to wear it hanging vertically in a low slung sheath, front and center. As an advertisement for manliness, it’s right up there with the codpiece. The advantage is, it’s really hard to defend yourself, or carve your dinner, with a codpiece.