10th-14th century, Crusades period and the period of siege warfare in general, before the development of of effective gunpowder. Iron, 7 3/8" length with butted seam conical socket and elongated diamond section head with thickened flared conical point of blunt form to prevent sticking into wood but capable of penetration into thatch as used for roofs of superstructure within castle walls and fortified towns. The medial with opposing fins pierced with two holes each side for binding incendiary material (oil or fat soaked rages) which would penetrate soft inflammables but bounce off wood or masonry, hopefully landing on a more easily ignited material. The head was mounted on a large wood shaft and fired from a Ballista, or large stationary crossbow (Arbalese) which allowed for adjustment of trajectory based on previous shots as with artillery. Sound excavated condition with some chips to the socket base. Exceedingly rare-not a single example in any museum collection known to us.