Complex sentence: Pressure from the French government led to a law that did not allow the name "cognac" to be used; it was ratified by the Dutch Supreme Court in a trade treaty with France on 1 June 1956.
Split into simpler sentences: Pressure from the French government led to a law that then definitely no longer allowed for the name "cognac" to be used. It was ratified by the Dutch Supreme Court in a trade treaty with France on 1 June 1956.