Bailey was the most common grain in the viking age (in Scandinavia). The Danish word for barley; “byg”- means grown grains. The archaeologists think that barley crackers flour have been common.
Neither barley and oat flour courses the dough to raise because they do not have any wheat gluten, so both grains are good for crackers and crispbread.
I baked a batch of these the other day and they are really lovely. I baked them on a dry skillet. I have also tried to bake them on a pizza stone in a hot oven, but that courses them to raise a little. It take some time to bake the whole batch on a skillet, but the problem with the oven is of course that there is heat all around the crackers.
I store mine in a tin so they don’t get too soft.
They are really tasty with cheese or salami.