While it was mentioned in passing during the show, the Dark Sister is a sword made of Valyrian steel and was passed down from Targaryen to Targaryen. In House of the Dragon, two special weapons get mentioned, namely the Dark Sister and the Blackfyre. The Dark Sister was special, as it was made solely for the wife of Aegon the Conqueror, Visenya Targaryen, and it would never require sharpening due to the steel it is made from. The last person to wield it was Bloodraven, aka, Brynden Rivers, the bastard son of King Aegon IV.
The Dark Sister is a lightweight sword made for easy handling, and it requires the least amount of upkeep due to its forever sharp edge. But in battle, it is sharp enough to cut a large number of enemies without losing its shine. Between the Targaryens, it was passed on till it reached Prince Daemon Targaryen, the brother of King Viserys I Targaryen, who was also the last Targaryen to have it until it was lost during the Blackfyre Rebellion.
Currently, the Dark Sister’s whereabouts are unknown, as, after the Battle of the Redgrass Field between Bloodraven and his half-brother Aegor “Bittersteel” Rivers, Bloodraven was exiled to the Wall after being stripped of his titles. It was said he probably took the sword with him, but only time will tell where it lies.
If you liked this article you can check out our other posts relating to the House of the Dragon TV show such as House of the Dragon – Aegon’s Dream and the Song of Ice and Fire Explained and House of the Dragon- Who is Ser Otto Hightower?