Pio Fede 1866 Rape of Polyxena Loggia des Lanzi
So, you were right if your first thought was "That looks like a work by Pio Fede to me.
More images here.
The basic story:
1) Polyxena was the daughter of Hecuba and the King of Troy.
2) Achilles killed Polyxena's brother Troilus in front of her.
3) Achilles falls in love with Polyxena .
4) Achilles kills another brother Hector.
5) Polyxena offers herself as a slave to Achilles in return for Hector's body.
6) Polyxena discovers Achilles heel betraying him to his brother Paris.
7) Paris kills Achilles
8) As he’s dying, Achilles asks that Polyxena “Sacrificed” to him.
9) Polyxena is stabbed to death.
10) Trojan War ends.
Bonus - Just Lion Around