[Davnoros]

There was once a long knife used in ancient Thrace called a sica. The blade is around 20" long and bent about 20 degrees near its middle. Single edged, sharpened on the inside of the angle.

Question: how would one forge such a blade, and keep the inner vertex from compressing, making sharpening more difficult? Seems to me that the metal would be just as likely to try to compress as the outer edge would expand. The one in question is third from the left in the attachment.

Any ideas?