Board Thread:General Discussion/@comment-174.59.143.163-20151018181316/@comment-6881629-20151018183236

The Skyrim Civil War started in 4E 201 with Torygg's death presumably very close to when Alduin attacks Helgen at the start of the game (same year), it may have been brewing since the Markarth Incident in 4E 174 but didn't start until 201.