After a botched military excursion in April of 2918 where the United Empire of Earth Navy failed to board a Pirate Drake Caterpillar resulting in the loss of a full platoon of marines and the armored shuttles carrying them, every major spacecraft manufacturer, in anticipation of a bid for an improved boarding ship, began racing to be the recipient of that bid.[2]
The request that ended up coming out of the military though was shocking to those involved. Rather than a call for a new ship, the military put out an all-call for ways to improve boarding. While it didn't outright say it wasn't considering new ships, it did signal to the major players that this may have been a PR move, rather than a true bid. As others dropped out or switched their focus to other methods of assisting boarding, only Aegis and Anvil remained designing ships.[2]
To develop its new ship, Anvil would operated under Codename Legionnaire and hide its development process under a story of assisting Roberts Space Industries in building out the Aurora LN's capabilities. Anvil would hire Grott Taylor to head the engineering team developing the Legionnaire, an unusual move due to Taylor's opposition to war. However, both Anvil and Taylor saw Taylor as the right person for the job believing that they'd be able to save lives by perfecting boarding.[2]
Just as development was beginning the UEE put a stop to the public boarding ship improvement process forcing Anvil's engineers to increase their level clearances and the rest of the Legionnaire's development process remaining classified to this day. Some have speculated that the reason for the increase in security clearance needed was due to the Navy successfully obtaining a Cleaver, a Vanduul boarding ship, and making it available to the Anvil team to examine throughout their development process.[2]
By 2920 Anvil flew its first Legionnaire prototype. Two short years later in 2922 they made a full squadron of test models were activated. By 2925 with UEEN backing, testing, and training, the ship became the centerpiece of the Navy's interception tactics.[2]
During a training exercise in 2932 the Legionnaire earned its legendary status. Mid atmospheric re-entry improperly stored external munitions exploded blowing off a third of the ship. Every functioning alarm blared while the ship itself attempted to rework itself to the ever changing flight model it was now taking on. After a successful crash landing both the pilot and co-pilot attributed their survival to the ship.[2]
During Invictus Launch Week 2952 Anvil activated the portion of its contract that enabled sale of the ship to civilians.[2]