Type D2 from Schleswig is a low shoe that was in use in the 13th and 14th century. The shoe is closed with a lace above the instep. Below where the lace is tied there is an eliptic opening. The lace is threaded through several slits all around the foot.
The pictures below show a number of production steps: Cutting out the upper, preparing the soles, completing the upper, sewing it to the sole together with a rand, attaching the heel stiffener and closing the shaft.
The completed shoe below is an earlier prototype-like version with the upper in one piece and without a leather band that nomally goes with the top edge of the upper.
Schnack, Christiane. Die mittelalterlichen Schuhe aus Schleswig – Ausgrabung Schild 1971 – 1975, Ausgrabungen in Schleswig, Bericht und Studien 10, Karl-Wachholtz-Verlag, 1992