In 4 ABY, during the Galactic Civil War, the MC75 Star Cruisers the Accordance and the Temperance were in the Core Worlds defending the Hosnian system when they were met by an Imperial armada.
The Imperial armada launched a surprise attack on the Core Worlds at the same time as the Battle of Endor and battled the two MC75 Star Cruisers. During the battle the Accordance was destroyed but the Temperance rescued the survivors and went on to win the battle against the armada.
The Temperance became the flagship of Vanguard Squadron and was temporarily placed under the command of General Hera Syndulla. The Temperance also served in the New Republic Defense Fleet.