Monarchs put on expensive celebrations to show off their wealth, power, and authority. But in 1971, the Shah of Iran would go a step further by organizing an event that would become known as the biggest party ever.

The occasion was to celebrate the 2,500th anniversary of the first Persian Empire’s establishment by Cyrus the Great. No grand hotels or other sorts of infrastructure were present to hold a large event. So instead, the party was scheduled to take place in the ancient Persopolis ruins in the desert. Throughout the entire year the party was prepared, articles about it appeared in newspapers. Additionally, a film director was hired to capture the event on camera. Hollywood icon Orson Welles narrated the movie’s English version, which was then broadcast in a number of theaters all over the world. The cost of the party varies depending on the source. The Shah’s administration estimated the price to be at $17 million. Meanwhile, Iranians estimated that the event must have cost around $500 million, which is equivalent to over $1 billion in modern currency.

But many historians believe that the party was one of the reasons that brought about the Shah’s government’s fall. The Iranian people were not invited, nor were the ministers. It was a celebration of Persia without its citizens, who made it one of the biggest and most powerful empires in history.