Context: Bahrain's prime minister, Sheikh Khalifah bin Sulman Al Khalifah has been in the post since 1970, making him the longest serving non-elected prime minister.

Question: Which non-elected official has held the longest term as prime minister?
Answer: Sheikh Khalifah bin Sulman Al Khalifah

Question: When did Khalifa first take the post of prime minister?
Answer: 1970

Question: What country does Khalifah serve for as prime minister?
Answer: Bahrain

Question: who is the longest serving elected prime minister?
Answer: Unanswerable