Ilioupersis   or  The Sack of Ilion by Arktinos of Miletos,  776-7
The work survived only in references to it. Scholars have reconstructed the episodes it contained on the basis of other evidence from antiquity, part of which is how scenes of the "Sack of Troy" were represented in art.
 

Episodes
The fall of Troy and the wooden horse.
Aeneas escapes carrying his father Anchises on his  back, along with his young son
    Askanios.
The Lesser Ajax rapes Cassandra who had taken refuge in the Sanctuary of Athena
    which outrages the rest of the Achaeans.
Priam and Hector's son Astyanax are killed by Neoptolemos.
Helen is recovered by Menelaus and led to the ships.
Polyxena is sacrificed on Achilles' tomb.

Apollodorus Epitome 5.21 "Neoptolemus slew Priam, who had taken refuge at the altar of Zeus of the Courtyard."
Apollodorus Epitome 5.23"And having slain the Trojans, they set fire to the city and divided the spoil among them. And having sacrificed to all the gods, they threw Astyanax from the battlements1 and slaughtered Polyxena on the [p. 241] grave of Achilles."

Louvre G152 by Brygos Painter ca. 475:
Scenes from the "Sack of Troy"
Munich 1700 by Antiope Group ca. 510
Revelry on battlements
Palladium
Crouching Priam
Neoptolemos kills Astyanax
Naples 2422 by Kleophardes ca. 475
Palladium
Neoptolemos kills Priam with boy on lap
Louvre G152 by Brygos:
Neoptolemos kills Priam with dead Astyanax
Malibu 83 AE 362 by Onesimaos (potter:Euphronios) ca. 500
tondo:N. kills P. with dead A.
Bologna by Niobid Painter ca. 460

 

Here is the question. Have the Brygos and Niobid Painters CONFUSED things accidentally or intentionally?
 
 
 
 
 

(For an idea of the complications behind this subject take a look at the second century C.E. "tour-guide" Pausanias' account of Polygnotus' monumental wall-paintings in the Lesche of the Knidians at Delphi)