In case you are wondering about the bleeding corpse and the upside-down scull or just looking for another history role-model… The lady in question is Rosamund, one of the few historical figures that actually had a life like one of Shakespeare’s plays characters.
To cut the long story short… (if possible)
In an attempt to secure a male heir, Alboin (the king of before mentioned Lombards) took her as his wife. Alboin was noted for his cruelty towards her; his most famous act of cruelty was reported by Paulus Diaconus, who states that at a royal banquet in Verona, Alboin forced her to drink from the skull of her dead father (which he carried around his belt), inviting her “to drink merrily with her father” .
After this, she began plotting to have her husband, Alboin, assassinated. Thus, Rosamund met with the king’s arms bearer and her lover, Helmichis, who suggested using Peredeo, “a very strong man”, to accomplish the assassination.
Peredeo refused to help, and that night mistakenly had intercourse with Rosamund, who was disguised as a servant. After learning that he had committed adultery with his king’s wife, Peredeo agreed to take part in an assassination attempt in fear of the king’s retribution. After the great feast, Alboin went to bed inebriated, at which point Rosamund ordered the king’s sword bound to his bedpost, so that should he wake in the middle of the assassination attempt, he would be defenseless. Alboin did wake, only to find himself unarmed. He fended off his attackers temporarily with a footstool, but was killed.
Read here what happened after (and before)