Battle of Rapture

The Battle of Rapture (3 November 2552 – 9 May 2553) was a major engagement of the  in which an alliance of Covenant separatists fought loyalist forces for control over the colony of Rapture.

It was both one of the earliest and most intense battles of the conflict, characterized by fierce close quarters combat and a level of mass-unit ground warfare seen in few other theaters. After months of fighting, the battle ended in costly defeat for the loyalists, who were forced into full retreat from the colony by the separatist alliance, losing a key foothold at the heart of the Kiel Expanse as a result.

Background
Though a small and rugged world, Usu'a–known in the human English language as Rapture–has been a crucial asset to the Covenant empire's expansionary efforts beyond the Kiel Expanse since the 4th Age of Conversion. The many matériel foundries, deuterium-tritium refineries, and agricultural habitats that dot its surface, as well as the several dozen repair-and-refit platforms and drydocks in its orbit were essential in maintaining the crusading armadas operating on the frontier. Additionally, much of the planet's strategic value also lay in its local interstellar jump points (IJP), which allowed abnormally brief faster-than-light travel even when compared with some other IJPs; this meant the Covenant could assemble immense invasion forces and deploy them across vast distances of space with unusual speed and efficiency.

The obvious advantages Rapture afforded were not lost on the High Prophet of Truth and in his plot to oust the Sangheili from the Covenant, the Hierarch moved to consolidate his hold on the colony. In August 2552, Truth's scheming resulted in the appointment of a new Minister of Conversion–Glom Bashk, a political ally–assigned to Rapture to serve as the colonial administrator and oversee fleet logistical operations directly. That same month, he also began the process of replacing the local Sangheili security detail with a Jiralhanae force led by Baladus, a general loyal to Chieftain Tartarus. With these staff changes, Truth hoped to secure Rapture as a key staging area for rapid assault, supply, and asset denial operations across Covenant territory once the coup against the Sangheili was openly declared.

Unfortunately for the Prophet and his conspirators, however, several factors surrounding Rapture that they failed to foresee eventually surfaced. First, no one realized just how delayed the transition of responsibility between the Sangheili and Jiralhanae would be. On 1 November 2552, three months after the reassignment order was given, roughly 40% of the Sangheili garrison was still present on Rapture. Additionally, they failed to predict the loss of Unyielding Hierophant and its fleet on 13 September 255, which inadvertently led to the movement of hundreds of military assets, most handled by the Elites, through the Ora system; between September and November, there was rarely a day in which Sangheili-controlled vessels weren't in the skies above Rapture. Finally, the Jiralhanae simply failed to account for the loyalty that the colony's Unggoy, Lekgolo, and Huragok populations held for their former Sangheili commanders.

These three aspects, together, amounted to circumstances that completely changed how the outbreak of the Great Schism on Rapture would take place. Rather than the swift, decisive conquest that Truth was hoping for, the struggle for the colony would be a long, drawn-out slog.