The interactive timeline starts with the "legend" of Satoshi Nakamoto, the anonymous "creator" of Bitcoin. I use all of those quotes because no one really knows who Nakamoto is, and while it's agreed he's from Japan, the name and the location may just be a pseudonym that actually refers to a group of people, all of whom worked on the currency. It skips forward to a patent application for a system that looks a lot like Bitcoin, the launch of the official Bitcoin website, and the release of the Bitcoin project on SourceForge in 2008. From there, it takes off to the first Bitcoin transaction, the first block to be mined, and of course, the ever-increasing difficulty of mining Bitcoin and the incredible lengths to which some people go to do it.
The timeline also includes things such as government reactions to Bitcoin and exploits and hacks that have shaped how the currency has matured. Though the timeline can get a little cluttered, it's worth a browse if you're interested in the history of Bitcoin, what it's all about, and how it moved from obscurity to the evening news.