What does the cryptic crossword clue "Puritanical tsar demolished crumbling citadel (6,5)" mean?

The wordplay uses an anagram. anagram of TSAR + CITADEL = STRAITLACED The answer is STRAITLACED.

Puritanical tsar demolished crumbling citadel (6,5)

Daily Mail Cryptic #16946 | 12 Across | 2022-10-14 flower