Complex sentence: At the end of World War I with the Treaty of Rapallo signed in 1920, the island was once again handed over to Italian Rule, until 1947, when the Islands, along with Istrian Peninsula, were returned to Croatia.
Split into simpler sentences: At the end of World War I, with the Treaty of Rapallo signed in 1920, the island was once again handed over to Italian Rule. This lasted until 1947 when the Islands, along with Istrian Peninsula, were returned to Croatia.