Complex sentence: Trying to secure his archaeological artifacts from ancient Halych and drawings of the cathedral in Krylos before the Soviet occupation of Western Ukraine, Jaroslaw Pasternak hid them in an undisclosed location shortly after he emigrated to Germany, where he died without disclosing the secret place.
Split into simpler sentences: Trying to secure his archaeological artifacts from ancient Halych and drawings of the cathedral in Krylos before the Soviet occupation of Western Ukraine, Jaroslaw Pasternak hid them in an undisclosed location. Shortly after he emigrated to Germany, where he died without disclosing the secret place.