Clan Wren was one of the clans that belonged to the house, Vizsla. They were Mandalorian warriors who were both allies (Ursa and Tristan) and members (Sabine) of the Rebel Alliance and artists (Sabine and Alrich).
Clan Wren originated from Krownest, their ancestral home. They were led by a countess, Ursa Wren and her husband, Alrich, who took his wife's last name. During the Clone Wars, Clan Wren was associated with the Nite Owls and Death Watch. In 21 BBY, Alrich and Ursa's first born daughter, Sabine was born, followed by a son, Tristan Wren. They were rivalled with Clan Saxon (which was also of House Vizsla). During the Clone Wars, Ursa was involved in the Siege of Mandalore.
While Alrich, Tristan and Ursa remained loyal to the Empire, Ursa disowned her daughter when she stood out against the Empire and did not seek Sabine out in order to protect her. While Sabine became a rebellion leader and a member of the Ghost crew, who she considered family, Tristan was forced to become a member of the Imperial Super Commandos led by Gar Saxon, and Alrich was taken prisoner by Saxon to use as leverage over Ursa.
In 2 BBY, with the interventions of Sabine, who bested the clan's leader Gar Saxon, in combat. Kanan Jarrus offered for the clans to joint he Rebel Alliance. However, despite defeating Saxon, Ursa Wren refused to join the rebellion in favor of fighting a second Mandalorian civil war and believed, in the chaos, the clan and Mandalore would grow stronger.
Later in the year, Ezra Bridger and his droid, Chopper, Sabine's compatriots, returned to Krownest, hoping for the Mandalorian clan's aid. Initially denying them, Ursa believed she owed Ezra and the rebellion help because they reunited her with her daughter. In return, Hera Syndulla lent Clan Wren Ezra, Kanan and Chopper to help restore the Clan's patriarch and Sabine's father, Alrich Wren. The Clan and the members of the Ghost later took on Tiber Saxon, Gar's brother, with Ursa's former commander and companion, Bo-Katan Kryze and Sabine defeated Tiber by turning her own weapon, the Justice, against them. The clan then professed their alliegence to Bo when she presented the Darksaber.
Afterwards, Sabine joined the rebellion once more, acknowledging that while her family on Mandalore could take care of themselves, her family in the Ghost crew needed her more.