The Last War
The most recent significant event in the Eberron Campaign Setting is an event called the Last War. It refers to a series of conflicts in Khorvaire over 102 years that began with a dispute over the throne of the Kingdom of Galifar and the ruling of the Five Nations.
Two years prior to the end of the Last War (994 KR), the nation of Cyre was destroyed in an incident known as the Day of Mourning. This event helped expedite the end of the Last War. Now, the region that was once Cyre is referred to as The Mournland and is the home of living spells, strange denizens, and a militant sect of warforged led by one called the Lord of Blades whose avowed goal is the total domination of the continent by the warforged at the expense of all “flesh and blood” humanoids. Those in the Mournland do not heal naturally, and magical healing has no effect. For all these reasons, few people enter the region.
The Last War officially ended in 996 KR, with the Treaty of Thronehold, as each of the Five Nations and most of the nations that broke off during the war officially became independent.