Firefox does the same thing too unfortunately, and it doesn't seem like it can be turned off.
It's a real pita for the same reason. Needed to look at browser history older than a few months and discovering it's all been deleted (by Firefox) was a very unpleasant experience.
Seems to be a needless data loss "optimisation" (sic), but I have no idea what the real world use case for that would be.
I wrote a script (https://github.com/osmarks/random-stuff/blob/master/histrete...) to dump a Firefox places.sqlite database to a separate SQLite database for long-term storage (I run it nightly). It seems to delete stuff based on some combination of visit frequency and last visit time.
I suspect they need to do this to keep history searches fast, since I also separately hacked a bunch of `about:config` options to retain more history and they run quite slowly now, particularly on my phone.
browser.history.maxStateObjectSize and places.history.expiration.max_pages (both accessible through about:config) should be the settings to modify. Do a web search for those properties to get more information on how they interact.
There's a good chance an about:config setting lets you change it. FF has a ton of detailed settings but most are hidden.
On my setup the "manage history" window goes back a bit over 6 months. Unfortunately the list entries don't show a date, so I can't give more precise numbers.
It's a real pita for the same reason. Needed to look at browser history older than a few months and discovering it's all been deleted (by Firefox) was a very unpleasant experience.
Seems to be a needless data loss "optimisation" (sic), but I have no idea what the real world use case for that would be.