Battle of New Tharsis

The Battle of New Tharsis was a minor but strategically-significant battle of the Human-Covenant War.

Background
When the UNSC recaptured Harvest in 2526 and fought to hold it for the next five years, most of war material, manpower, and ships needed to contest it were funneled there via the long Primary Librae Route, which connected the planet to a number of important industrial centers in the Mid-Rim. This allowed the colony to remain a thorn in the Covenant's side, allowing raids deep into enemy space and give reinforcements a second angle of approach into the Centaurus Region. However, its discovery by the Covenant could allow an invasion fleet to bypass most of the UNSC's defenses and hit their soft industrial underbelly. And perhaps, if a good fleetmaster recognized the opportunity, even continue straight on into the very core of the Human Sphere.

In late 2527, the Harvest Campaign suffered a major setback when the Covenant's Fleet of Valorous Consecration decisively defeated the orbiting UNSC battle group, thereby establishing space supremacy over the entire Heimdall system. During the fighting, they managed to attach a probe onto the hull of the destroyer as it escaped from the system, which promptly traveled down the Primary Librae Route for emergency repairs. With the route's discovery now known to him, Fleetmaster Soeu 'Nar Ireetanee immediately sought reinforcements and the blessing from Imperial Admiral Xytan 'Jar Wattinree to carry out an attack so far behind enemy lines. It took over a month to convince 'Wattinree to authorize the attack, and a second month to receive the reinforcements and supply ships he needed for his success.

'Nar Ireetanee led his fleet against Madrigal in February 2528, easily overwhelming the light defenses and glassing the colony. However, his campaign quickly came to a halt when he clashed with Vice Admiral Preston Cole's Third Fleet, losing most of his fleet in the process. The only way he was able to salvage it was to feint a retreat back to Harvest, fooling Cole into pursuing. Damaged and with only a dozen warships remaining, 'Nar Ireetanee nevertheless decided to regroup and attack the next target on his list - New Tharsis.

The Battle
The remnants of the Fleet of Valorous Consecration arrived in the 16 Librae system on March 28, 2528. Hostilities did not begin immediately, as the Covenant fleet wanted to confirm whenever New Tharsis was worth attacking, and the UNSC defenders had to reorganize their ships so the 114th Rapid Strike Squadron was brought back up to strength.

Beginning April 3, Fleetmaster 'Nar Ireetanee led Valorous Consecration to battle aboard his flagship, the Ascended Tribulations, so he could land forces on the surface to establish a ground presence. The first two space battles were UNSC victories that forced his forces to retreat, although he was successful in allowing two to run the blockade. Eleven UNSC frigates were lost and both cruisers damaged at the cost of four enemy frigates and corvettes. More importantly, Rear Admiral India Martel was killed in action. As a result of the weakened UNSC Navy, the Covenant was able to smash through the UNSC fleet during the third space battle and reinforce themselves. Seeing as the space portion was largely over outside of orbital fire support, and wanting to remain close to the developments on the surface, Commodore-Admiral Ashok Raymond permanently transferred his flag to the UNSC Endeavour.

With the battle shifting over to land, the Covenant made quick and sure gains. At first, the UNSC defense efforts were focused on simply withdrawing their forces away from the Accardo Peninsula, where the Covenant had made landfall. Bases assigned as fallback points were swiftly overrun and destroyed, although a concerted defense of Port Granitis meant that the UNSC was able to save most of their maritime fleet in the region. Each defeat, however, gave the UNSC more and more time to establish firm defensive lines, and forced the Covenant to commit more and more of their valuable troops to each engagement. Although with enemy naval vessels still unable to be directly engaged safely, at least without risking more irreplaceable frigate and destroyers, actually stopping them proved more and more difficult.

That changed with the Battle of Cascate Tonanti, New Tharsis' capital city. Planned to finally turn the battle in favor of the UNSC, Raymond and the UNSC Army Brigadier-General, Pierino Pinto, both collaborated to turn the city into a target that required the attention of the Covenant's few warships to take. To do this, massed anti-aircraft batteries were installed throughout the city, and Pinto leveraged the civilian population into retooling shopfronts into bunkers and factories to producing small arms. Meanwhile, Raymond would concentrate his remaining frigates and destroyers to provide further air defense and intercept any attempts to outflank the city. In secret, a handful of naval coilguns intended for cruisers were installed in camouflaged bases.