This tune is originally a Romanian song collected by Bela Bertok, which became a powerful English anti-war song. The song has been covered by Maddie Prior and June Tabor, in their incarnation as the Silly Sisters. Also the song was arranged in 1980 by Andy Irvine and Jane Cassidy to a Bulgarian tune. This is the only version that I know with Eastern European music (all along the song).
The story of Andy Irvine's version told by himself:
"This one started as a Romanian song collected by Bela Bertok in the early part of this century. A friend of mine, Jane Cassidy and myself re-wrote it a few times and put it to a Bulgarian dance-song tune".
The rhythm and harmonies are Bulgarian. The song (and the dance) is a paidushka 5/16 rhythm. The lyrics could refer to any of the never-ending border campaigns against the Ottomans (though others think that they could have been written about the Napoleonic war...). Blood and gold has to do with the contrast between the gold used in banners and decorations on weapons and helmets and the blood realities of the war.
This is the Gurt Lush version.