Here are two details of the actual sewing in progress. Take care not to pierce one yarn with the other's needle, as you cannot pull the seam tight anymore afterwards then - another reason why especially with those double seams I prefer to use those blunt needles

Time needed to prepare the holes, pitch the yarn and sew both from the inside and outside down the length: 2 hours

Finally the lower end of the back seam needs to be attached to the part of the leather that forms the middle layer of the caligae sole. Note that I did not sew down all the way to the end but left the last part open. First I needed to cut off little triangles from the lowest part of the heel, as those edges would overlap when folded inwards, because of the rounding of the heel.



Push the unsewn section inward now and press and form the leather to get the heel form right.



That is the way I want it to be, so I use the left over yarn from the back seam I just did. The length should be just enough to sew this on. I use a double stitch again for better durability, as walking puts a lot of stress on this seam. Each end of the yarn is used for one side, going forward for about 5 stitches and then backward again using the same holes so that both ends meet again in the middle, where they can be knotted then.
(I cannot attest to the historicity of this way to close the back seam at the heel, as to my knowledge unfortunately none of the researchers so far bothered to explain or show/draw this in detail even though it is a crucial point in construction IMHO. I have written Carol van Driel-Murray on this matter and am waiting and hoping for an answer at the moment.)

Time needed: 30 min

After closing the back seam I chose to apply a seam protection. This was not always done, but is known from a number of finds. Here is the piece of leather I prepared for that, already pierced every 6mm to take up the 3mm broad band of leather I cut from a piece of alum-tanned and therefore white leather to make for a nice color contrast. The widening at the lower end will go in between the middle and lower sole for extra stability

After piercing the caliga leather at the same distance as the protective strip I laced the white leather band through both layers. Note that you do not need 3mm wide cuts for the leather band to go through, a somewhat larger hole pierced with an ordinary (or if you have one, flat) awl works just as well.

Here is the finished back. The white leather strips end inward, where the can be tied and sewn down to keep them in place. Instead of the (in my case white) leather parchment can also be used.



After oiling, the light brown protective leather will be almost the same color as the caliga leather.

Time needed to prepare leather parts and thread the strip through: ca. 2h 30 min