The Elephantine Papyri and Ostraca consist of thousands of documents from the Egyptian border fortresses of Elephantine and Aswan, which yielded hundreds of papyri and ostraca in hieratic and demotic Egyptian, Aramaic, Koine Greek, Latin and Coptic, spanning a period of 100 years in the 5th to 4th centuries BCE. The documents include letters and legal contracts from family and other archives, and are thus an invaluable source of knowledge for scholars of varied disciplines such as epistolography, law, society, religion, language and onomastics. The Elephantine documents include letters and legal contracts from family and other archives: divorce documents, the manumission of slaves, and other business. The dry soil of Upper Egypt preserved the documents. Hundreds of these Elephantine papyri span a period of 100 years, during the 5th to 4th centuries BCE. Legal documents and a cache of letters survived, turned up on the local "grey market" of antiquities starting in the late 19th century, and were scattered into several Western collections. A number of the Aramaic papyri document the Jewish community among soldiers stationed at Elephantine under Achaemenid rule, 495–399 BCE. The so-called "Passover Letter" of 419 BCE (discovered in 1907), which appears to give instructions for the observance of the Festival of Unleavened Bread (though Passover itself is not mentioned in the extant text), is in the Egyptian Museum of Berlin. The standard reference collection of the Aramaic documents from Elephantine is the Textbook of Aramaic Documents from Ancient Egypt. Between 1815 and 1904, all discoveries were unprovenanced and came via informal discoveries and antiquities dealers; only later were they understood by scholars to have originated from Elephantine. The first known such papyri were bought by Giovanni Belzoni and Bernardino Drovetti; a number of Aramaic letters and a demotic letter were presented by Belzoni to the Musei Civici di Padova in 1819 and three hieratic pieces from Drovetti – and the Turin Aramaic Papyrus – were deposited at the new Museo Egizio in Turin in 1824.