Complex sentence: For many years the batons were all on display at Apsley House however on 9 December 1965 there was a robbery in which three items were stolen one of which was the Russian Marshal's Baton.
Split into simpler sentences: For many years the batons were all on display at Apsley House. However, on 9 December 1965 there was a robbery in which three items were stolen, one of which was the Russian Marshal's Baton.