Timeline JS - Beautifully crafted timelines that are easy, and intuitive to use.

Because there are so many details to the styling, this is not exactly simple, but, if you have some technical capacity, you can override TimelineJS's CSS rules and have complete control over the look of the timeline. For details, see Using the TimelineJS CSS selectors. You will need to be able to instantiate the Timeline in javascript on your own page. (There is no way to override the CSS using the iframe embed.) Then, either in <style> tags in that page, or in an external stylesheet, you can specify CSS rules changing some or all of TimelineJS's default presentation. The basis of TimelineJS's styles are in these files, which use the Less CSS preprocessor.

Aeon Timeline: The timeline tool for creative thinking Beautiful web-based timeline software