Having been established on Krownest, Clan Wren eventually came to be one of the vassal clans of House Vizsla, and were known to be part of the Death Watch led by that family. Clan Wren was powerful enough that the husband of Countess Ursa Wren took the name Wren upon marrying into the family from a less powerful clan, and the name was also passed to their children Sabine and Tristan. Unfortunately, Clan Wren was later ostracized after the Galactic Empire used weapons that Sabine helped develop against the Mandalorian people, and Sabine fled after speaking out only to receive no support from her family. Tristan then joined the Imperial Super Commandos in an effort to regain some standing for his family while his father was held captive on Mandalore, but Clan Wren's lessened status was indicated by the muted colors of the armor worn by its members.
Gar Saxon, Imperial Viceroy, later targeted Clan Wren for destruction, using the presence of Jedi Kanan Jarrus and Ezra Bridger at the Krownest compound as his justification. However, Fenn Rau of The Protectors and Sabine, who had traveled to Krownest in company with the Jedi and in possession of the Darksaber, rallied Clan Wren to fight against the Super Commandos, minus Tristan who sided with his family. The commandos were handily defeated, and Sabine used Ezra's Lightsaber to defeat Saxon in a duel and reclaimed the Darksaber from him; Ursa then killed Saxon while he was taking aim to kill Sabine. Clan Wren was thus left to prepare for the chaos that would result from the death of the Imperial puppet, with Sabine and Rau remaining on Krownest to aid them.
Clan Wren soon became embroiled in the Mandalorian Civil War, serving as the anti-Imperial counterpart to the pro-Imperial Clan Saxon, and were hard-pressed to defend themselves from their enemies and their Imperial allies. When Ezra came to Krownest in the Nightbrother seeking aid for the beleaguered rebel forces caught up in the Battle of Atollon, Countess Wren was reluctant to commit forces. However, seeing Ezra's determination to return to the battle and Sabine's determination to go with him, she agreed to provide a small force of Fang Fighters and to allow any willing warriors to join the mission. The force succeeded in taking out the lone remaining Imperial Interdictor, enabling the remnants of the Rebel force to escape the system. Ursa then expressed her sympathies for the Rebel losses to Captain Hera Syndulla, before expressing hope that the rebellion forces would be able to assist Clan Wren in their own struggles with the Empire.