|General Akkir||Duke Mormant|
| 6 Tallarn Desert Raider Regiments
3 Chaemosian Royal Guard Regiments
The Chaemos Rebellion took place in late M38 when the Imperial governor of Chaemos was overthrown by his subordinate, Duke Mormant. An Imperial retribution force was sent to Chaemos to put down Mormant's rebellion.
Six Tallarn Desert Raiders regiments and three loyalist Chaemosian Royal Guard regiments, under the command of Tallarn General Akkir, were ordered to completely destroy Mormant's armed forces, which consisted of 30,000 men and several dozen large artillery guns. Although the Imperial forces were outnumbered and outgunned, they had the advantage of mobility due to the large number of Rough Riders in their ranks.
Mormant's army was deployed between two rivers; an area known locally as the Broadsword due to its long, pointed shape. The two armies camped within a mile of each other, in plain sight of the enemy army. The traitor forces attacked just before noon, using his artillery to soften up the Tallarn positions and his infantry forces to drive them back. This continued for four hours, with the Imperial forces falling back after each small skirmish. This left the traitor forces strung out and isolated. Akkir exploited this a few hours before sunset when he launched his counter-attack. He divided his forces in two, sending 3000 Rough Riders around the flank to take out the artillery and forming the other half into a single division that crushed each enemy formation piecemeal. The remaining traitor forces were caught in a pincer between the Tallarn infantry at the front and the Rough Riders to their rear. Over the next few days Mormant's forces were completely destroyed. The Battle of the Broadsword became one of the Tallarns' most famous victories in a large engagement.