Britannica Interactive Timelines is an interesting tool from the Encyclopedia Britannica.
It allows students to click on a topic, such as Exploration or Medicine, and then pick a year. A very short explanation of what was going on during that year related to the topic you chose then shows-up. In addition, if you click on it you will be taken to a section of the online version of the encyclopedia that will give you more information on that topic.
Unfortunately, it won’t work with the Student Edition of the Britannica, so if you click to get more information the entry might or might not be accessible to English Language Learners.
However, the timeline feature is definitely accessible. I’ve had students use it to develop their own timelines. To encourage students to put it into their own words, though, I have them write no more than three words down for each entry in their notes. Then, when they get back to class they have to put it into their own sentences.
I’ve placed the link on my World History page under Sites That Cover Many Periods of World History.