There's a legendary blog post about this:
https://auntymuriel.com/2012/12/23/asterix-in-translation-the-genius-of-anthea-bell-and-derek-hockridge/
Also a rare chance to plug my community, which has posted a fair share of Asterix and other BD goodies: https://piefed.social/c/eurographicnovels
EDIT: As a matter of fact, I'll be posting the first three pages of Asterix' new Lusitania adventure in a few minutes... EDIT2: Done! :D