Talk:Teutons/@comment-24444169-20150611123832/@comment-24444169-20150611124721

Found it, it is reported on a few italian books of heraldy that it was used in contrast with the guelphs (often bearing st. george's cross), as a sign of support to the Empire (the H.R.E.). It is also called "Cross of John the Baptist" but I've just translated it into English - you won't find a word about it.

Probably a flag used during the guelph/ghibelline wars mostly, much later adopted or revisited by unrelated countries. An example could be this one, though not identical. http://en.wikipedia.org/wiki/Flag_of_the_Sovereign_Military_Order_of_Malta