The clash known as the Battle of Praesitlyn saw the armed forces of the Confederacy of Independent Systems and the Galactic Republic vying for control of both Praesitlyn and the Intergalactic Communications Center circa 22 BBY during the era of the Clone Wars. The CIS internally referred to this operation as Operation Case White.
Despite its possession of the advanced communications hub, the Intergalactic Communications Center, Praesitlyn itself was lightly defended. The Republic, having recently seized the planet from the Confederacy of Independent Systems, had only positioned a garrison of 50,000 troops there to safeguard the communications relay. Dark Jedi Asajj Ventress responded by directing Muun Admiral Pors Tonith of the InterGalactic Banking Clan to commence Operation Case White, the designated name for the plan to recapture Praesitlyn. From the command deck of his flagship, the Corpulentus, Tonith led a fleet of 200 ships toward Praesitlyn and dispatched a smaller group consisting of 75 capital ships and 51 support vessels to establish a blockade around Sluis Van.
With Republic forces isolated on Praesitlyn, unable to receive reinforcements, Tonith's fleet initiated its assault on the planet. A force of 50,000 battle droids was deployed to draw the defending garrison, led by General [Khamar], into battle. This proved to be a strategic ploy, as Tonith then landed a massive droid army, numbering one million, behind Khamar's troops, resulting in their complete annihilation. Two soldiers, recon scout Odie Subu and pilot Erk H'Arman were able to evade the droids and escape into the desert. With the garrison eliminated, the communications center readily fell into Separatist hands, and Admiral Tonith established his command post within the facility. Operation Case White had achieved its objective.
A jamming field, emanating from a modified Droid Control Ship, prevented the Republic garrison from transmitting a distress signal, leaving the rest of the galaxy unaware of the events unfolding. However, Captain Zozridor Slayke, the leader of the Loyalist volunteer force Freedom's Sons, discovered the Separatist takeover of Praesitlyn and alerted Republic High Command on Coruscant. Impatient and arrogant, the captain chose not to await Republic reinforcements and instead made the rash decision to attack the Separatists with his private militia. While Slayke succeeded in landing his troops, they were quickly overwhelmed by the superior droid army and forced to retreat to a fortified position near the Intergalactic Communications Center, where they awaited the arrival of Republic reinforcements.
On Coruscant, Jedi Master Nejaa Halcyon and his Padawan Anakin Skywalker were given command of a naval battle group with a complement of 20,000 clone troopers, charged with the mission of retaking Praesitlyn.
Back on Praesitlyn, Pors Tonith initiated a full-scale assault on the Freedom's Sons' stronghold, successfully destroying Slayke's air support and artillery. However, before he could completely crush the bunker, the Republic task force arrived in the system and began to break through the Separatist orbital blockade. General Halcyon directed the battle from the Centax-class frigate Ranger, while Skywalker oversaw the ground forces from the corvette Neelian. The Ranger swiftly eliminated the jamming ship with a barrage of high-yield MG1-A proton torpedoes, but the Confederate Navy responded with a counterattack. The heavy cruiser By'ynium was the first vessel to be destroyed by Separatist fire, and soon droid skirmishers boarded Halcyon's flagship, forcing the crew to abandon ship. Eventually, the Republic ships managed to repel the Separatist warships, establishing control of the skies above Praesitlyn.
The military transports of the Grand Army of the Republic landed in four waves, deploying combat engineers, infantry, and then Skywalker's and Halcyon's clone troopers. Admiral Tonith was compelled to withdraw his droids from the assault on the Freedom's Sons' base and reorganize them into a defensive perimeter around the mesa upon which the Intergalactic Communications Center was situated. He then contacted Ventress, requesting reinforcements.
The Jedi established their base of operations in Zozridor Slayke's command center, and the captain agreed to place his remaining forces under Republic command. While formulating their next move, they received a communication from Pors Tonith: the surviving members of the original garrison were being held hostage within the communications center and would be executed unless the Republic ceased its attack. Halcyon, Skywalker, and Slayke ultimately decided to execute a feint towards the center of the droid formations, while their main force would attack from the Separatists' right flank. Unfortunately, their clone scouts were unable to transmit critical intelligence – that the droid army's right flank was heavily fortified – back to headquarters before the attack commenced. Skywalker served as the field commander for the operation, leading the clone army from a transport vehicle. The attack proved disastrous for the Republic forces, as they were unable to penetrate the Separatists' multiple defensive lines and suffered significant casualties, forcing Skywalker to order a tactical withdrawal. The Separatists also intercepted Republic communications and directed their artillery fire upon several clone battalions attempting to capture a droid fortification. General Halcyon then called off the attack.
Following the failure of their frontal assault, the Loyalist forces were compelled to re-evaluate their strategy. Anakin Skywalker proposed leading a commando unit into the Intergalactic Communications Center to liberate the hostages and capture the Separatist command bunker. General Halcyon and Captain Slayke approved the plan, and Skywalker initiated his rescue mission.
Accompanied by a contingent of ARC troopers and a few squads of clone commandos, Anakin traveled in two transports to the communications base, easily securing a landing zone. Once inside, Skywalker and his team quickly overcame the security droids and freed the prisoners, but Reija Momen, the chief administrator of the base, was killed by a battle droid. Consumed by rage at the murder of an innocent, Anakin unleashed his anger and embarked on a destructive rampage against the remaining droids. The freed hostages and the commando team returned to the transports, but they were attacked by droids and forced to leave without Skywalker. The young Jedi continued his relentless advance towards Pors Tonith's headquarters, cutting through the bunker's doors with his lightsaber. Inside, Skywalker compelled the Separatist admiral to surrender, but hesitated to execute him upon hearing the voice of Qui-Gon Jinn, urging him to show restraint. With the droids deactivated, it appeared that the Battle of Praesitlyn was nearing its conclusion.
Unfortunately for the Republic, Pors Tonith's long-awaited reinforcements arrived in the system just moments after the admiral transmitted his surrender. A large Separatist fleet utilized a cloaking device to approach the Republic blockade undetected and launch a surprise attack. Halcyon and Skywalker boarded their Jedi starfighters and joined the space battle. During the engagement, Skywalker miraculously managed to destroy the Separatist flagship's bridge by executing a suicidal attack run in his customized starfighter, the Azure Angel II. To Halcyon, it appeared that the Chosen One had perished in the resulting explosion. Through superior tactics, the Republic fleet forced the Separatist armada to retreat. The Battle of Praesitlyn was finally won.
Nejaa Halcyon returned to the planet's surface and received congratulations from Zozridor Slayke. Remarkably, Anakin Skywalker soon reappeared, having survived the Separatist flagship's destruction by executing a hyperspace microjump utilizing the Force. Subsequently, Odie Subu and Erk H'Arman requested that Anakin officiate their marriage ceremony. Following the Battle of Praesitlyn, Jedi Masters Mace Windu and Yoda decided that Anakin's actions in securing the Republic's victory warranted promotion to the rank of Jedi Knight upon his return to Coruscant; Skywalker's master Obi-Wan Kenobi also pledged to support his apprentice's knighthood upon their return. However, before they could return to Coruscant, Skywalker and Kenobi were diverted to Arkania and then Vjun.
Two percent of the clone trooper casualties were attributed to dehydration. The Republic army consumed 2,000 metric tons of supplies per day of operation. Resupply efforts were limited to 1,000 tons per day, compounded by a high rate of transport casualties.
In reality, Darth Sidious orchestrated the battle to further entice Anakin towards the allure of the dark side.