I think the Crusades were the worst holy war ever.

There. Problem solved. Unless you wanna kill a few hundred thousand people and go to war for a few hundred years.

(If I'd said "The holocaust", I could've Godwinned this thread, but that wasn't really a holy war.)

That's quite an interesting point - if you restrict holy wars to the "my imaginary friend is better than your imaginary friend.... fight!" kind then you are probably correct.

I'm trying to think of other real "holy wars" - the 30 Years War is perhaps the only other major one I can think of. I guess most other "holy wars" are really justs lingering fall out from conquests Ottoman invasion of Europe, Ireland, .....

The 30 Year War was really a Holy war?

Consider that Sweden, one of the big participants, was financed by the famously Protestant country France! :-)

Does "War on terror" count as a holy war? Then we could have a contest after all. It's not a few hundred years yet, but give it some time to unfold ;)

Interesting... how were the Crusades larger/worse than the muslim expansion all the way to Spain/Balkan/India?

(Let us bunch the Crusades as one single example, at least for this argument.)

(The Huns/Mongols were religiously tolerant and motivated by conquest, right?)

The Ottoman Empire was religiously tolerant and motivated by conquest as well. (The irony of the 20th century is that if the empire could have staved off its breakup for just a little longer, they would have had Iraq's oil wealth to back them up and very well could have developed into a modern superpower.)

A point, re muslim expansion to the Balkans. But still, just the Spain/Persia/Iran expansion makes the Crusades look like a tea party with centenarians.

But where the Ottomans religiously tolerant in all periods?

It seems the Turks where really disliked by their subjects (both in Middle East and in the Balkan), where did that come from, then?

Sigh, s/Iran/India/

I declare "O rly?" vs "Ya rly" the worst holy war ever.

Neither side will ever give an inch, and vast armies of anonymous have lobbed internets at each other, killing a few StarCraft players in Korea and memeing millions upon millions more, with more arriving every day.

The worst holy war would be a holy war about holy wars: which holy war is the worst?