- "Commander, bring up the Lightning Squadron."
"I want Lightning up here, now!"
- ―Mace Windu and Commander Ponds
The unit was established at the start of the Clone Wars to handle special recon missions. Lightning Squadron consisted of ten ARF Troopers specially trained to operate AT-RTs and could be divided into two five-man squads, or lances, each led by a sergeant. A lieutenant was the commanding officer of the entire unit. Despite being subordinate to higher officials, the unit maintained a certain amount of autonomy and often worked behind enemy lines, far from any immediate help.
During its first action, the Battle of Herdessa, six days after Geonosis, the unit disabled the central control computer on board a Multi-Troop Transport after crossing the battle lines. This temporarily shut down the droid forces, which allowed the 121st Regiment free passage past Confederate artillery.
During the Battle of Muunilinst, the squadron led three other AT-RT recon units in harassing IG lancer units and prevented an organized response to the main force's encirclement of the InterGalactic Banking Clan stronghold.
At the Battle of Daalang, the unit crossed through the Separatist energy shield that protected an anti-orbital mass-driver cannon, rushed past its defenses, and destroyed the shield generator. This allowed the Star Destroyer Eliminator to bombard the cannon as Lightning Squadron rushed back to friendly lines.
Under the command of General Mace Windu and Commander Ponds, it participated in the Battle of Ryloth. The unit greatly helped in the liberation of the world from Emir Wat Tambor. Lightning Squadron was a division of Windu's force during the offensive to free Ryloth's capital.
Windu led his force to the capital via a cliffside path. This was a risky decision that did not escape the notice of the Separatist defenders. In an attempt to neutralize the Republic forces before they became a strategic threat, the Separatists sent a tank division to box the walkers in by disabling the leading and rearmost units before destroying the entire group. As the Republic force fell under heavy fire, Mace Windu ordered the deployment of Lightning Squadron's AT-RTs. Mace Windu led Lightning Squadron in a charge that completely routed the Separatist tanks, freeing the rest of the walker division to advance to their objective. They later took part in storming the capital city of Lessu alongside Cham Syndulla's freedom fighters.
Razor and Stak were two particularly notable members during this battle. The pair served as Windu's companions for much of the campaign, accompanying him during his dealings with Syndulla's freedom fighters. Later, he took them along during his attempted infiltration of the plasma bridge control center in a Separatist convoy, which was spoiled by a Separatist inspection. The Separatist droids tried to drop Windu, Razor and Stak into the canyon below by shutting off the bridge's power, but with Windu's Force powers, they crossed safely. The Jedi Master held off the Separatist defenders so the pair of ARFs could storm the control center and enable the liberation force to enter the city.
Late in the war, the unit saw action during the Siege of Saleucami before being transferred to Kashyyyk. Following Order 66 and the establishment of the Galactic Empire, Lightning Squadron continued in Imperial service, still under the 91st Corps that was now within the Imperial Army.
Under the Empire
During the Galactic Civil War, the unit retained its AT-RT walkers and was augmented with armored AT-PT and 74-Z speeder bikes, among other vehicles. Fighting against Rebels often meant probing their defenses and armaments by harassing Rebel bases, ahead of the main army, thus gaining vital intel for the main operation. It operated mainly under Army control, despite having clones in its ranks. As the war continued, members of the scout trooper division of the Stormtrooper Corps were transferred to the unit, and Lightning Squadron gained a floating status where it worked under different branches depending on the current goal.
Following the Battle of Endor, the squadron participated in the Ryoone campaign and, over the period of a month, participated in a series of engagements against the mercenary organization Churhee's Riflemen. However, the squadron was eventually defeated.