UNSC-Sangheili Joint Task Force

The UNSC-Sangheili Joint Task Force was a fleet formed by combined elements of the Sangheili Republic Navy and the UNSC Navy, as part of the UNSC-Sangheili Joint Operations Force. The fleet made its debut during the Battle of Sanghelios in the Brute War. The fleet would play a big part in the war, including being present in the assault on the Jiralhanae homeworld. The fleet would later become a primarily reinforcement fleet, useful in attacks on the planets of either species.

Conception of Fleet
In 2570, two years before the death of Thel 'Vadam on Sanghelios, the Arbiter and leading members of the UNSC Navy met on Cairo Station to discuss an alliance between the newly-formed Sangheili Republic and the UNSC. As part of the agreement, the UNSC-Sangheili Joint Operations Force was formed, featuring soldiers from both races, as well as forming the Joint Task Force. A specific training station was set up to train Humans to fight alongside Sangheili, and vice-versa.

Brute War
In 2572, the shaky peace between the Jiralhanae and the Sangheili was shattered when the Jiralhanae, along with Kig-yar privateers, attacked civilian shipping within the Sangheili Republic. While the UNSC wished to stay neutral, various Sangheili elements from the JTF were used to protect shipping. The task force would stay neutral until the UNSC received a desperate call for help from Sanghelios.

Battle of Sanghelios
When the Battle of Sanghelios first began, the Jiralhanae and their Kig-Yar pirates were able to overwelm the defenses over the planet. It was in this chaos that Thel 'Vadam was killed by a Jiralhanae Chieftain in the fight for the Sangheili capital. Before his death, however, the Arbiter managed to send a message through slipspace to Earth, begging the UNSC to get involved. This decision brought the joint task force into play. When the ships left for Sanghelios, the fleet had firepower that was equal to almost three-fourths of the of the UNSC Home Fleet.

The fleet was almost able to rend the fleet in half, but the command elements managed to escape. While the planet lay in mourning for their dead, the UNSC and the Snagheili took the fight to the enemy.

Battle of Doisac
Three years after Sanghelios, the fleet launched a daring assault on the Jiralhanae homeworld, using Long Range Stealth Orbital Insertion Pods (some specially modified for Sangheili usage) to launch 1000 Orbital Drop Shock Troopers and Sangheili commandos onto the planet's surface from slipspace. The tiny pods managed to escape detection by the Jiralhanae until the capture and destruction of half of the planet's surface-to-space mass accelerator guns, and by then the task force was exiting slipspace over the planet.