Slain, but resurrected in Byzantium later (8)

I believe the answer is:

istanbul

I'm a little stuck... Click here to teach me more about this clue!

'byzantium later' is the definition.
I can't judge whether this definition defines the answer.

'slain but resurrected' is the wordplay.
'slain but' anagrams to 'ISTANBUL'.
However, I'm not clear how the anagram is indicated.

'in' is the link.

Can you help me to learn more?

(Other definitions for istanbul that I've seen before include "Former Turkish capital" , "Port and former capital of Turkey" , "Nail bust in the Turkish city" , "Modern Byzantium" , "foreign port" .)

I've seen this clue in The Times and The Sun.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.