Also, the timelines are overlapping too much, for example it says something happened, then moves locations and says some other thing previously happened (that it just told you about).
Finally, lots of little things thrown in at the end; "the Ionian revolt happened and Persia spent time and effort conquering them. [3 paragraphs] Also Persia was mad at Athens for helping which kicked off the war". Not built in a very narrative or easy to track way.
Full disclosure: I work for Esri, a competitor to Mapbox.
This probably could have been implemented more quickly and easily, with better usability and performance, via StoryMaps or ArcGIS StoryMaps. The product is tailor-made for exactly this sort of website/project.
Btw, it's suppose to autoscroll on Play. That is the feature. Its what I call the 'storyteller mode'. I am thinking of using text-to-speech to read each event before proceeding to the next event so the 5 second delay is an arbitrary setting for now.
If you don't want the autoscroll, then you can just scroll the old fashion way on the sidebar. When you do the map will flyTo() the corresponding event.
The play feature is only if you want the events to autoscroll for you and its part of a storyteller feature I'm working on. So you don't have to use it to scroll.
Well. I don't think it is a good idea. In text-based content, you need to wait for some input from the user that he's done reading this part of the page and is ready to proceed further. And in your case, the page scrolls extremely fast. I'm no slow reader, but I barely manage to read the chapter headline before it scrolls.
Unfortunately I never had the chance of a paying project that involved timelines, or libraries around it.
Persians were the prominent tribe in Achaemenid empire which was destroyed by Alexander. But remainder of Persians among other tribes that formed the empire later on freed themselves from Macedonian rule and eventually and gradually pushed them out.
Even though the Macedonians occupied the land, they adopted the form of government and were influenced by the culture and Persian way of life. They themselves also had an influence on those empires, naturally.
Unfortunately the website is lacking in painting a comprehensive picture of Persian or those other tribes that formed the Persian empire or perhaps I couldn’t find it.
I do plan on creating other History maps on the Ancient Persian empires:
Would love some feedback when those are done. Thanks for the constructive feedback. I always appreciate those.
That will be awesome to read more about those pieces of history in the form of this website. Well appreciated.
But yes, eventually the Caliphate was invading Europe using cannons to reduce formerly state of the art castles 1000 years later.
The tribes I was talking about were Parthians  and Sassanids . These are long before Islam and Muslim invasion of Iran and they were once part of Achaemenid empire.
I don’t know what you exactly mean by power structure but the form of government (i.e. Central government and Satraps) were adopted by and outlived the Macedonians.
You can get more information here (or simply Wikipedia):
edit: fix typo
-scroll without hovering over the text itself
-not having to wait for each section to load when scrolling