The Purple Ribbon is seen in both Blood and Sand and War of The Damned. The ribbon was tied around Sura's thigh in the The Red Serpent as Spartacus leaves to serve in the Roman auxillary. Following the couple's enslavement, the ribbon was retrieved by Glaber and given back to Spartacus at Batiatus' Ludus.
During his "test" against Crixus, Spartacus drops the ribbon onto the combat platform. He later uses the ribbon to trip Crixus as Crixus stood upon it. Throughout much of his time as a Gladiator, Spartacus wears the ribbon tied around his arm. It serves to symbolize his reason for living: saving Sura from slavery. He is later seen using his scant water ration to clean the ribbon after he and Varro are punished by being thrown into the waste pit.
When Batiatus forces Spartacus to fight in The Pit, Batiatus, knowing the importance of the ribbon, asks that Spartacus remove it lest it be sullied with the stain of dishonor that surely accompanies battling in a place like The Pit. When Spartacus redeems himself from The Pit after saving Batiatus' life, it is returned to him by Batiatus.Spartacus continues to wear it until Sura arrives at the ludus. When she dies of her wounds, Spartacus places it in her funeral shroud and it is burned along with Sura.
Strangely, the ribbon reappears in War of the Damned when Spartacus is speared 3 times by Crassus' men. As he is reeling from the impalement, Spartacus sees the ribbon blowing across the ground and has a reflection to the time when he first tied it around her thigh, many years before.