Monarchs have large feasts with the utmost elegance throughout history to demonstrate their money, prestige, and influence. But in 1971, the Shah of Iran would take it a step further by planning a party that would go down in history as the largest celebration.

The event marked the 2,500th anniversary of Cyrus the Great’s founding of the first Persian Empire. There were no luxurious hotels or other types of infrastructure to accommodate a large gathering. So instead, the party was set to take place in the desert-based ancient Persopolis ruins. The Shah wanted to display his wealth and might to the world. Newspapers ran stories about the party all during the year it was planned. A film director was also employed to document the occasion on camera. The English version of the movie was narrated by Hollywood star Orson Welles, and was then distributed to several theaters all around the world. The cost of the party varies depending on the source. According to the Shah’s government, it cost roughly $17 million. But in some sources, the celebration cost between $100 million and $150 million. Meanwhile, people in Iran calculated that the celebration must have cost around $500 million, which is more than $1 billion in today’s dollars.

Still, a lot of historians consider the party to be one of the climactic events that ultimately led to the downfall of the Shah’s government in 1979. Neither the ministers nor the Iranian people were invited. It was a celebration of one of history’s largest and most powerful empires without the people who gave it its size and might.