I am reading history for pleasure only, but below is what I do with history in my obsidian. Maybe it can offer some help.
The center of the history notes are #reign and #period
#reign represents the period during which an individual manages a polity.
EDIT: I should add that although #reign carries the name of the ruler, it is in my mind not merely about the ruler. It is a representation of a period and context, which is a concept common in east asian reigns, where the emperors name his own “periods”.
I will always give #reign metadata as below.
reign:
begin: YYYY
end: YYYY
For notes like [[roman empire]], which is a #polity in my files, they don’t have exact begin date or end, simply because I find it against nature. Empire doesn’t fall into the world on a particular year, it evolves.
So, everything except for #reign gets #period/1500s, or #period/0300s in my notes so I can explore hidden connection in graph mode. Mostly helpful in comparing what was happening around the same centennial.
Having a clear timeline of reigns then matter to me. So whenever I create new reign, I have a templater that inserts a timeline item in the reign note. This will automatically capture the metadata “begin” and “end” in my note. And the note record will be updated into my [[polities]] file, as shown in the red bars timeline. The [[polities]] file contain other indexes, but won’t explain further as those aren’t directly related to your concern.
<span
class='ob-timelines'
data-title='<% tp.file.title %>'
data-date='<% tp.frontmatter.reign.begin %>'
data-end='<% tp.frontmatter.reign.end %>'
data-class='reign'
data-type='range'
>
</span>