Where did the name "Lawliet" come from?

this is L's last name. other than this information, there is nothing else specified

Huh...i never knew about that name...And how is it a last name?

At first I thought this was a swali about how the writer came up with that name. That would be interesting to know. But apparently it is not.
Lawliet is L's last name. wewe learn this in "L Change the World".

i think its french au british some european name

I heard it's a British name... though I live in the UK and ain't ever heard the name before. Maybe it's old-fashioned? I'll be hyped when I find someone with the name though.
Prove it's his name; It's in "L Changes the World" movie. Don't know about the novel as I yet to read it.
It's also in Death Note 13: How to Read. It's in his bio saying it's his true name. The book also comes with a True Name card. (Which looks awesome, btw.) Which also has the name "L Lawliet" on it.
I believe it's pronounced Law-Leet. Though I could be wrong. But that's how I say it as that makes the most sense to me.