The engraving of the double-headed eagle on the sword is quite careless; likely it was done at the request of the owner and by a not very skilled smith.
I vote for Austro- Hungarian. The curliqued filling of the body somehow does not look Russian to me. Strangely, it reminds me of Greek or Balkan blade engravings ( I am having a cold, and a mix of fever and over-the-counter concoctions may explain my hallucinations
)