WASHINGTON (AFP) - The United States on Friday returned to Russia 21 historical documents, some hundreds of years old, that were stolen from the national archives in Moscow and St Petersburg more than a decade ago. The documents, including decrees signed by the last Russian czar Nicholas II and 18th-century empress Catherine the Great, were handed over to Russian ambassador Sergey Kislyak by US Immigration and Customs Enforcement (ICE) director John Morton in a ceremony at the Russian embassy in Washington. Today, quite simply, we right a wrong, Morton said, calling the return of the documents a happy ending to a sad tale of the theft and the sale of Russias cultural heritage. Kislyak hailed the joint US-Russian operation that helped recover the papers that reflect important moments in the development of the Russian empire and the Soviet Union. Thanks to this wonderful cooperation between Russia and the US, a big piece of Russian history is going back home, he said. The documents are just a fraction of around 1,000 historical papers that went missing from Russias national archives between 1994 and 2002. ICE agents became involved in the operation to recover the documents earlier this year when the Russian government agency in charge of protecting cultural property contacted the US agency after tracking down several dozen of the historical papers, which were on sale at five US auction houses. Another 10 documents have been located in the United States and will be returned to the Russians, said Morton. Most of the documents were given up willingly by their owners when they learned they had been stolen, and the US auction houses were not party to the theft of the documents, which changed hands several times before turning up in the United States, Morton said. Former US ambassador to Russia James Collins told AFP he thought the documents might have been stolen to be marketed for autographs. Think of how you would feel if you had Thomas Jeffersons letters, with his signature on them. Thats what these documents are like, Collins said, referring to the third president of the United States and the main author of the Declaration of Independence. Among the yellowing papers was a decree signed in 1792 by Russian empress Catherine the Great, on which she had signed her name with a flourish, blotting a large loop at the top of the first letter with black ink. The signature of Emperor Alexander II swirled across the page of a decree dated 1867, written in old Russian Cyrillic script. Two of the papers bore the signature of the last Russian czar, Nicholas II, who was executed with his family after the Bolshevik revolution of October 1917. A typewritten personnel list, an order to troops and a military appointment were all signed by World War II Soviet military commander Georgi Zhukov. The documents were offered for sale or had traded hands for prices up to 15,000 dollars when ICE agents tracked them down, Morton said. But we dont approach the theft and repatriation of these documents from a monetary perspective, he said. Documents like these are priceless. How do you value documents that reflect the history of one of the great nations in the world?