My personal preference is Librewolf. Not sure about Zen, hopefully someone else will jump in

Waterfox is one option. its UK based. I find it a little faster than librefox out of the. I use the container tabs extensively for my IT work juggling dozens of customer login details and profiles.

Have a look at Mullvad browser made by a Swedish company.

I haven't been able to confirm precisely, but the Midori browser appears to be from Spain or at least Europe. Their website only comes in English/Español and the only events they have listed as attending have been in Germany. It's Gecko-based, so it's "Firefox-ish". It also takes Firefox add-ins, which is nice.

I've been using it for a couple weeks now and it's been working fine. Spotify hiccups on it, but that's the only site I go to regularly that doesn't like it.

Just my 2 cents as a web developer.. I don't have any reason to quit Firefox (or Thunderbird). Yes the hole communication about PPA was a disaster and opt out is not ideal, but on the other hand the Gecko engine is so important for the open web. Without Mozilla it will surely die soon. So we end up with Blink and Webkit, both controlled by US big tech companies.

So, is it really such a good idea to penalize Mozilla in the long term? I don't think so.

If PPA really is unacceptable for you, opt out. At least its a good idea to read about this standard and then make a decision.

i think vivaldi and ecosia browsers are also european

ZenBrowser, LibreWolf, Mullvad Browser

I use Startpage, a dutch alternative. Pretty basic but solid browsing.