According to the myths, Aigisthos killed Agamemnon whilst being his wife Clytemnestra’s lover, but was killed himself in revenge by Orestes, son of Clytemnestra and Agamemnon.
Few ancient sculptures better show how complicated it can get trying to date a piece, particularly on stylistic grounds alone. When found it was immediately said to be a Roman work imitating Archaic Greek, which was a popular and common style in the first century BCE there. Later it was claimed it was from some two hundred years before that, imitating Etruscan work of even earlier. Neither of these theories quite rings true, and now it is thought to be not a stylistic imitation but a straight copy of a lost Archaic Greek piece. The Romans were fond of imitating Archaic styles, but direct copies are rare.
The original shows signs of having been burnt
Copenhagen, Ny Carlsberg Glyptotek 1623
Furtwängler: Antike Gemmen III, 277, fig.140 (for comparison with bearded heads on Etruscan gems)
Poulsen: Katalog over Antike Skulpturen Ny Carlsberg Glyptotek, 47, pl. 111
Jahrbuch des Deutschen Archäologischen Instituts 82 (1967), 246-
Richter: Ancient Italy, 31
Fullerton: The Archaistic Style in Roman Statuary, 203
Strong: Art in Ancient Rome I, 20
Found at the end of the nineteenth century, in the precinct of Diana at Lake Nemi in Ariccia outside Rome