Short answers, pulled from the story.
The Derveni papyrus is an Ancient Greek papyrus roll containing a philosophical commentary on an Orphic poem about the birth of the gods. It dates to around 340 BC, during the reign of Philip II of Macedon, making it Europe's oldest surviving manuscript.
The Derveni papyrus was discovered on the 15th of January 1962 at a nobleman's grave near Thessaloniki in Central Macedonia. Archaeologists Petros Themelis and Maria Siganidou recovered its charred remains from ashes atop the tomb's slabs.
The Derveni papyrus was found at Derveni, on the road from Thessaloniki to Kavala, in a nobleman's grave belonging to a rich necropolis of the ancient city of Lete. It is now held at the Archaeological Museum of Thessaloniki.
The Derveni papyrus is considered the most important textual discovery of the 20th century for the study of Greek religion, the sophistic movement, early philosophy, and the origins of literary criticism. In 2015, UNESCO added it to the Memory of the World International Register as the oldest known European book, the first Greek item to receive that designation.
The Derveni papyrus contains a commentary on a hexameter poem attributed to Orpheus, used in the mystery cult of Dionysus, alongside a theogony describing Nyx, Uranus, Cronus, and Zeus. Its earliest, worst-preserved columns describe rituals involving the Erinyes, daimones, and the magi, and quote the philosophers Heraclitus and Parmenides.
The Derveni papyrus was published in its entirety in 2006-44 years after its discovery, by a team of researchers from Thessaloniki led by Tsantsanoglou and colleagues. Three partial editions had appeared before then, and later work by Valeria Piano and Richard Janko used digital microphotography to read previously illegible passages.