Thanks to George R. R. Martin, Elden Ring has a comprehensive history that we see snippets of in-game as we traverse the ruins of several bygone eras. This means there's a lot to unpack before we even set foot in The Lands Between, but given that most of it is inferred through dialogue and item descriptions that are easily missed, it can be hard to pinpoint when exactly certain events took place. So, one fan has put together a complete timeline.
It splits Elden Ring's past into three distinct eras - Godfrey's Reign, Radagon's Reign, and The Shattering. And underneath these three eras, u/octobersveryown616 lists key events, battles, attacks, and each war. It all starts with Marika and Godfrey's marriage during the War of The Giants, followed by Godfrey's conquest of The Lands Between in which he sealed away Destined Death and the Golden Order was formed. During this, we also see the War against Ancient Dragons and both the first and second Liurnian wars.
However, Godfrey was banished after these two conflicts and eventually Liurnian unrest bubbled into a civil war, but after that, things quieted down. That is until the Night of the Black Knives and the subsequent shattering of the Elden Ring, which led Godrick to flee to Stormveil with Radahn not far behind, later attacking him in that same castle. This was followed by Leyndell's assault on Mt Gelmir and Malenia's campaign against both Godrick and Radahn. Then, the timeline closes with the Battle of Aeonia and the start of the game when we enter the scene.
While the timeline is mostly accurate, there are some parts that other lore sleuths on the Elden Ring subreddit have disputed. One claim is that the "War against Ancient Dragons" doesn't take place during Godfrey's conquest, and actually unfolds after his banishment given that Godwyn is the figurehead during that campaign. The Liurnian Civil War also likely took place after the shattering of the Elden Ring.
Another key point raised is that the invasion of Mt Gelmir mentioned seemingly never ended given that we find Leyndell soldiers still attempting a siege. That being said, the timeline is fairly precise, and serves as a perfect jumping-on point if you want to dig into Elden Ring's extensive history - there's a lot of ground to cover, so pick a favourite boss fight and you can find out just what they were up to before we finally slew them.