In antiquity, Mediterranean shipbuilders devised the mortise-and tenon method of joining the hull planks to one another. Instead of overlapping adjacent planks and fastening them together, shipbuilders placed the planks in an edge-to-edge position and joined them by means of wooden links (tenons) inserted in slots (mortises) carved in the two planks. The tenons were then firmly secured within the mortises by pegs through the plank and its tenon. When the craft was placed in water, the wood swelled, forming a watertight fit. This joining technique has been discovered in vessels dated as early as the 14th–13th centuries B.C.; it went out of use in the Byzantine period.