The Bismark Archipelago, the area that you lot are wondering about, so I shall talk about the Third Battle of the Bismark Archipelago:
Operation Name: Operation Dynamo
Timeline: January 1st 1233 - May 26th 1234
Armies: Slovan Imperium Ground Forces and Navy. Dragon Liberation Army.
Leaders: General Deathclaw, Field Marshal Drenox (Slovan Imperium). Conscript Son De Vere (DLA).
Numbers: 30,000 Ghost Stalkers (Infantry), 40,000 Ghost Stalkers (Navy), 10,000 Dragons (Infantry), 2,000 Dragons (Navy), 200 U-Boats, 150 Warships, 50 Airships (Slovan Imperium). 10,000 Ghost Stalkers, 500 Dragons, 1 Golem, 200 Wyverns (DLA).
Casualties: 20,000 Ghost Stalkers (Infantry), 40,000 Ghost Stalkers (Navy), 6,700 Dragons (Infantry), 1,350 Dragons (Navy), 195 U-Boats, 148 Warships, 49 Airships (Slovan Imperium). 9,950 Ghost Stalkers, 350 Dragons, 1 Golem, 180 Wyverns (DLA).
Result: Slovan Imperium Victory and complete surrender of the DLA.
History: The Third Battle of the Bismark Archipelago was the most brutal battle of the War, surpassing the Seige of Warfang and the Battle of Mosingrad (where the main comic starts). Tensions between the DLA and the Slovan Imperium were high, and eventually the DLA struck first. On January 1st, 1233, when the few troops garrisoned at the Archipelago were celebrating a new year, the entire army of the DLA attacked and quickly gained a foothold on the west most island in the Archipelago. The attack quickly turned into a defence as the Slovan forces repeatedly counterattacked, taking heavy losses in the process. For the following 6 months, Sinholus ignored the battle despite the requests from the remaining Slovan Officers begging for help. In those 6 months, the DLA pushed further into the Archipelago until they were close to capturing the last island. However, General Deathclaw and Field Marshal Drenox ignored orders and gave the troops at the Archipelago some much needed backup. For the rest of the battle, it was a gruesome and bloody mixture of hedgerow, guerilla, and the occasional artillery battery. Due to the never before encountered tactics, the Slovan Imperium took extremely heavy casualties throughout, which lead to the almost complete annihilation of the Slovan Fleet, 68th-109th Slovan Divisions and the complete destruction of the 31st Stormtrooper Battalion. It was worse for the DLA. Not only did they have to surrender because their entire army was dead or captured, but also because the DLA stronghold of Kronos was bombarded, napalmed, and gassed. As a result, 50,000 civilians died and the survivors were either captured and tortured, killed on sight or escaped to Mosingrad with all having an almost 100% case of combined trauma, burns and gas related wounds.