|Political and military information|
- Joseph Harper: "This is Fleet Admiral Harper, we are engaging the enemy!"
- Terrence Hood: "Negative, Admiral. Form a defensive perimeter around the cluster."
- — Fleet Admirals Joseph Harper and Terrence Hood as the Battle of Earth begins
Fleet Admiral Joseph Harper (service number 07959-90021-JH) is a human flag officer of the UNSC Navy. Towards the end of the Human-Covenant War, Harper commanded the Fifth Fleet, as well as the Marathon-class heavy cruiser UNSC Canberra, his flagship. Along with Fleet Admiral Terrence Hood, Harper led UNSC forces during the Battle for Earth in late 2552.
Preparing the defense of Sol
In the final years of the Human-Covenant War, Fleet Admiral Joseph Harper served as the commander-in-chief of the Fifth Fleet, taking command of the expeditionary fleet on January 20, 2548. His flagship was the Marathon-class heavy cruiser UNSC Canberra. In May 2552, Harper organized the defenses of Earth in preparation for a possible Covenant attack. Harper had all warships with functional MACs self-deployed or towed to rally points, and personally assessed the security team deployed by the UNSC Chevalier to Cairo Station in preparation of the arrival of Fleet Admiral Terrence Hood, Chief of Naval Operations. Following the Fall of Reach, all remaining forces of the UNSC Navy were consolidated into a single command grouping under the UNSC Home Fleet on September 5, 2552. Harper was appointed senior flag officer and given primary administrative and tasking authority over all aerospace assets within the Sol system, as per emergency security directives authorized by UNSC High Command and approved by the UEG Security Council. On October 9, 2552, the UEG Strategic Forecasting and Scenario Planning Group, as well as the Office of Naval Intelligence and the UNSC Special Topics Committee, concluded that humanity was almost certainly doomed following the losses sustained during the Covenant's invasion of Epsilon Eridani. However, Harper did not agree with this assessment.
On October 10, 2552, Battle Group Rhino of the Third Fleet approached twelve unidentified vessels with outdated civilian IFF codes near Enceladus. Upon approach, eleven of the vessels promptly fled the system, leading to Battle Group Rhino attacking the remaining vessel. The carrier UNSC Totem Lake was lost with all hands, and Battle Group Rhino disengaged and returned to the UNSC defense line. Vice Admiral Williams of the Third Fleet requested permission to reengage the remaining hostile vessel, but was denied by Harper. On October 13, 2552, anomalies were detected near Argyre Planitia on Mars. A team deployed by Naval Special Warfare Command discovered cloaked remote sensor platforms of undetermined origin. After consultation with Admiral Margaret Parangosky, Commander-in-Chief of ONI, Harper issued a priority-1 stand-down.
Battle for Earth
- "First echelon, you're with me—blanket those cruisers, take 'em out one by one. Second echelon, keep those carriers busy."
- — Fleet Admiral Joseph Harper, leading the Fifth Fleet
On October 20, 2552, the Battle for Earth began when the Covenant's Fleet of Sacred Consecration arrived in the Sol system, unaware of the system's human presence. Harper and Hood coordinated the orbital defense of Earth, with Harper leading the Fifth Fleet to engage the Covenant fleet while Hood commanded Earth's orbital defense platforms. Harper desired to engage the Covenant fleet on their way to Earth, though Hood had him form a defensive perimeter around Cairo Station's battle cluster. Harper led the first echelon of his fleet against the thirteen CCS-class battlecruisers of the Covenant fleet, while the rest of his fleet engaged the two CAS-class assault carriers. Despite substantial losses, the Fleet of Sacred Consecration eventually managed to break through Earth's defenses and launch a ground assault upon the planet.
Later in the battle, on November 17, 2552, Covenant fleet elements began excavating a Forerunner slipspace portal near the Kenyan town of Voi on Earth. Battle Group Victory vectored to support UNSC Air Force and Marine Corps forces clearing Type-27 Mantis emplacements nearby, allowing for Harper to authorize an in-atmosphere MAC strike against the Covenant's flagship, the Forerunner Dreadnought. However, the MACs had no effect against the keyship and the portal was activating, resulting in spatial distortions that damaged the artificial gravity systems of the nearby ships. The remaining Covenant forces, and a small group of allied UNSC and Sangheili ships under the Fleet of Retribution, entered the portal, leading to Installation 00 and ultimately the final battle of the war. Meanwhile, with the bulk amount of Covenant forces in the system gone, UNSC forces began a counteroffensive against the Covenant. Remaining Covenant forces fortified themselves across North America. On December 3, 2552, Harper directed Operation: MARSH FLASH, which successfully eliminated clusters of Jiralhanae leadership attempting to activate an artifact in Arizona, URNA.
On February 1, 2553, Harper no longer commanded the Fifth Fleet, though continued to serve in the UNSC Navy by at least April 6, 2554, compiling reports on the actions he took to prepare Earth's defenses for a Covenant attack.
When the city of Aranuka underwent reconstruction as part of the UEG's Rebirth initiative, an educational facility was constructed and named in Joseph Harper's honor. A notable student who attended Admiral Harper High School was Molly Patel.