Where does the sir name Lustgarten aka Lambert come from?

Question:

Where does the sir name Lustgarten aka Lambert come from?

I am trying to trace a relatives family history but can find no record of them, in the national archives records, only this name Lustgarten is linked to Lambert by way of an individual changing his name.
I've seen the name in Latvian marriges and death records on the web, but I always thought Lambert was an English name.
Can anyone shed a little more light on the subject.
My relative lived in the east end of London, before and after the second world war.

Best Answer - Chosen by Asker: The word Lustgarten in German means amusement park. German sounding names can be found in a number of countries besides the three that claim to speak German (Germany, Austria, and Switzerland). Czech, Slovakia, the Baltics, Denmark, Ukraine, Russia, etc. Lambert is a name that can have multiple origins also--Irish, English, even Scots. And Lamberti is an Italian name sometimes Anglicized to Lambert. I could well understand why someone with such a German sounding name as Lustgarten living in London might have changed it in the WW2 era.