On the 11th of November 3077, Lahti was one of four Free Worlds League worlds to be attacked by the Marian Hegemony. Lahti continued to be harassed by forces from the Marian Hegemony, and finally the planetary government grew so sick of the raids by IV Legio that they hired the Protectors to launch a punitive strike against IV Legio's home base on Trondheimal. Colonel Kawamura accepted the contract, although he was unwilling to provoke the Hegemony. He attempted to fulfil the contract by subcontracting the work to Havoc, Inc.. Havoc, Inc. made a less than stellar impression when they arrived on Lahti; disreputable to begin with, the mercenaries made a drunken arrival on Lahti that prompted Colonel Kawamura to call off the raid. One of Kawamura's officers, Lieutenant Fiona san Marcos, convinced Kawamura to launch the raid as a false-flag operation, using a company of Protector forces painted in Havoc, Inc. colors and deployed using Havoc, Inc. transport assets. San Marcos led the raid personally, inflicting damage on IV Legio and deliberately leaving evidence pointing towards Lahti.
Kawamura had deployed the Marik Protectors in anticipation of the inevitable IV Legio counterattack, and IV Legio arrived as anticipated, crashing into the Protector forces. Initially, IV Legio was able to tear through the Protector lines using Ravager battle armor, until Captain Doris Calhoun dropped a company of Kopis-equipped infantry onto the IV Legio battle armor and broke them. Kawamura's heavy armor successfully ambushed the IV Legio 'Mechs, pushing the Marian forces into the open for the Protectors' artillery forces to bombard; an attempt by the IV Legio aerospace fighter forces to relieve the pressure on the 'Mech forces was countered with fire from Partisan anti-aircraft tanks. The commanding officer of IV Legio, Prefect Alberich Winograd, realized that his forces were in a trap, and led them in an orderly retreat back to their transport vessels; Colonel Kawamura, impressed with the Marian troops' discipline under fire, parlayed briefly with Winograd. During that parlay, the two established a degree of mutual respect for each other, as well as a détente between the Hegemony and Lahti. Encounters between IV Legio and the Protectors after the battle on Lahti were marked by relatively little bloodshed and an almost cordial or ceremonial attitude between the two commands.
- Spotlight On: First Marik Protectors, p. 5
- Spotlight On: First Marik Protectors, p. 3, "Unit History and Description"