The original Black Watch was the fulfillment of several dreams. The first dream was that of Cosara Weaponries, then-producers of the Crab 'Mech, who wanted to expand their operations. The second dream was dear to the Northwind Highlanders, who had long craved the independence that Wolf's Dragoons and the Kell Hounds enjoyed in having their own private suppliers of military hardware. Finally, Captain Neil Campbell of the Royal Black Watch Company dreamed of creating a 'Mech that would symbolize the new spirit of unity in the Inner Sphere in their shared war against the Clans. He therefore pushed for the use of weapons and electronics built throughout the Inner Sphere. Many critics of the new design believed that its haphazard creation would be its downfall. It nearly was when the Jihad made the interstellar trade it depended on impossible.
         Cosara Weaponries quickly adapted to the new order of things though and modified the design. Using technologies produced on Northwind or smuggled in from the nearby Federation of Skye, Cosara soon began building everything on site. They have kept it under construction ever since, never losing access to the parts that make it possible to assemble it.

         The Black Watch is built around the same chassis as the SLDF's training 'Mech, the Crockett. Cosara Weaponries chose that design for its ruggedness and its jump jets - the latter an unusual feature on an assault 'Mech.
         Early in the planning stages, the engineers wanted to install an extralight engine. However, that soon changed because of the extent to which an XL engine makes a 'Mech vulnerable in battle. Though XL engines weigh less than standard engines, allowing a 'Mech to carry considerably more weaponry and equipment, they are also bulky, taking up vast areas of the 'Mech's torso. Attacks that damage the torso are therefore much more likely to inflict critical damage to an XL engine than to a standard model. Indeed, throughout the Jihad the standard-engine Black Watches often took critical damage that would have left other new BattleMechs a ruin on the field but kept moving towards the enemy.
         Of all the original weapons, only the Ultra Autocannon has remained. Now easily built anywhere with access to recovered Star League technology, it survived the Jihad with little difficulties. The MRM and Light Gauss Rifle soon became scare outside the Draconis Combine and Free Worlds League though. The Highlanders therefore asked that Cosara replace them with a standard Gauss Rifle and a set of the Multi-Missile Launchers recently introduced by Battle Magic. While they lost some range with the Gauss Rifle, they gained range back with the MMLs, allowing the Black Watch to start pummeling at long range and to get progressively more devastating as it closes with the enemy.
         The only weakness of the design is its complete and utter reliance on a supply train to keep fighting. While they have plenty of ammunition on board for a single battle, a longer campaign can quickly result in a Black Watch with empty bins. Such a Black Watch is all but helpless against any enemy, so Black Watch MechWarriors are taught to begin looking for the ammunition train when their bins go below fifty percent. Still, the amount of damage they can unleash while they have ammunition makes them an incredible design.

         The Black Watch is the symbol of the Black Watch Regiment, one of the few regiments permanently assigned to the Star League. Because of this they have also become a symbol of the Star League, and holovids of them fighting the Word of Blake are still in wide circulation even today. They are also used by the Northwind Highlanders and other mercenary units in the Allied Mercenary Command in need of a cheap but powerful assault 'Mech.