The Palatine Anthology, a codex compilation of 3765 poems in Greek, was once in Rome at the Vatican Library, along with other manuscripts in the Bibliotheca Palatina, but is now divided between the Universitätsbibliothek Heidelberg (Cod. Pal. graec. 23) and the Bibliothèque nationale de France (suppl. gr. 384). It is one of the two manuscripts on which the collection known as the Greek Anthology or Anthologia Graeca, is based; the other manuscript is the Planudean Anthology.
The bulk of the Palatine Anthology was based upon the compilation of Constantine Cephalas (Konstantanos Kephalas), a Byzantine schoolmaster who in about the year 900 excerpted all the major ancient manuscript collections. To material gathered by Cephalas, whose original compilation no longer survives, the compiler of the Palatine Anthology added Christian and "rhetorically descriptive" epigrams. A possible compiler of the Palatine Anthology was the 10th century poet, Constantine the Rhodian, three of whose poems are included in the anthology.
"In 1606 or 1607 [Claudius] Salmasius had discovered, in the library of the Counts Palatine in Heidelberg, the only surviving copy of Cephalas's early unexpurgated copy of the Greek Anthology, including the 258-poem anthology of homoerotic poems by Straton of Sardis that would eventually become known as the notorious Book 12 of the Greek Anthology. The newly discovered poems in the Palatine version were copied out by Salmasius, and he began to circulate clandestine manuscript copies of them as the Anthologia Inedita. His copy was later published: first in 1776 when Richard François Philippe Brunck included it in his Analecta; and then the full Palatine Anthology was published by Friedrich Jacobs as the Anthologia Graeca (13 vols. 1794-1803; revised 1813-1817). The remains of Straton's anthology became Book 12 in Jacob's standard critical Anthologia Graeca edition. It was only in 2001 that a full Greek-to-English translation of Book 12 was issued, by Princeton University Press" (Wikipedia article on Claudius Salmasius, accessed 02-03-2009).
Digital facsimile from Universitätsbibliothek Heidelberg at this link.