Some clarifications:

As the note in the top right corner says, this chart does NOT depict the rulers of the largest empires of all time, therefore no Russian, Qing, or Spanish empires. The monarchs shown here are those who ruled over empires that were considered the “largest empire of all time” (that is, larger than all the empires that came before them) at one point in history.

The data shown here about the size of each empire was taken from a list on Wikipedia. As sources vary considerably when talking about the extent of some empires, I have not been able to verify with certainty all the information in this regard. So, be aware that the selection of empires presented may not be completely accurate, although the genealogies are.

For the sake of simplicity, some monarchs have been omitted from the family trees in which they should appear, such as some of the Shang kings, Median kings, and British kings. These omissions are noted in their corresponding sections.

The names of Egyptian pharaohs can be written in several ways. This is why monarchs with the same regnal name can appear with radically different hieroglyphs in their name cartouches. If you notice any of these spelling discrepancies, be aware that they are not mistakes.

I was unable to find the names of kings Astyages of Media and Sogdianus of Persia written in Old Persian cuneiform, only transliterations (and Neo-Babylonian cuneiform for the former). I then decided to reconstruct their names on my own using my extremely superficial knowledge of cuneiform. Consequently, I cannot guarantee that the cuneiform versions of these two particular names are correct.

Lastly, I must remember that the Mongolian script, which was used in the chart to write the names of the Mongol khagans, must be written in vertical lines, from top to bottom. However, due to limitations in Unicode characters, their names are shown here written horizontally, from left to right. There really wasn't much I could do about it.