Smarting from the horrendous loss at Byron, Admiral Warrick needed a way to prove himself a capable leader in the eyes of his peers.
He planned a large-scale invasion of the Republic's former home system, Madrigal. To accomplish this, he would need the combined efforts of the Empire's two largest fleets: the 1st Emperor's Fist and 2nd Emperor's Sword. In addition, he was granted use of the recently-finished MAC ship, the most powerful single battleship ever fielded, capable of leveling an entire continent with it's RNL gun.
The attack, if successful, would be a crushing blow to the Republic's morale.
This invasion was also a test run for a new battle tactic employed by the Empire. Deployed in two ranks, each ship in the massive invasion fleet had a "twin", another ship of equal size and firepower. When one ship was locked on by an enemy ship, it would "tag out" with its twin, reducing damage taken immensely. Unsure of how to deal with the tactic, Republic defenders only managed a few hits at a time with their missiles.
The attack began on Madrigal III on September 15th, 3711. The entire fleet warped in at once, surprising the Planetary Defense Fleet. Dozens of Republican cruisers were destroyed before their calls for help were even acknowledged.
The first shot of the MAC was fired on September 17th, 3711, at an orbiting defense station. The power of the shot was so great that the husk of the station was launched into Madrigal III's gravity well. The kilometer-wide station fell to the oceans, causing tsunamis that drowned thousands.
The second shot was fired on January 5th, 3712, on Madrigal II. The entire north pole of the planet was decimated in an instant, and nuclear fallout spelled the doom for millions of people to the immediate south.
The Third and final shot of the Mac was also on Madrigal II, on December 31st, 3712, at its major population center--Madrigal Prime. Over a billion lives were snuffed out in an instant, and the city was leveled.
Several times, small Republic fleets would arrive in the system to try and break the siege, but to no avail. Many dozens of ships were lost as they tried to push the Empire back or evacuate civilians.
Once the planetary defense fleets had been decimated and the ground defenses annihilated, the Empire spent the next three years in an all-out ground invasion. The few surviving military outposts in the system could not call for outside help, the nuclear fallout so thick. Imperial ground forces had to wear hazmat suits just to survive the environment.
Overwhelming victory for the Empire. The MAC was a proven success and no more that thirty ships were lost to Republic fire, thanks to their new tactic.
Republic morale hit an all-time low with the loss of their once-homeworld.
over 10 billion lives were lost.