Complex sentence: The Communist Party of Indonesia (Indonesian: "Partai Komunis Indonesia", PKI) was the largest non-ruling communist party in the world prior to being crushed in 1965 and banned the following year.
Split into simpler sentences: The Communist Party of Indonesia (Indonesian: "Partai Komunis Indonesia", PKI) is a communist party in Indonesia that existed in throughout the 20th century. It was the largest non-ruling communist party in the world prior to being eradicated in 1965 and banned in the following year.