Two military planes carrying 17 tons of silver coins recovered from a Spanish ship sunk in 1804 have taken off from Florida. The treasure is being flown back to Spain after a nearly five-year legal struggle with the U.S.-based explorers who found and recovered it.

The planes that took off Friday were packed with more than 594,000 coins and other artifacts. Odyssey Marine Exploration, which is based in Florida, brought the coins to the U.S. in May 2007.