Clue: Prince hit hard by bishop and essayist taking part in immature liaisons (7,4)
Answer: CHARLES LAMB
Explanation: Prince hit hard by bishop and essayist taking part in immature liaisons (7,4)
Two ways to get to this answer: 
1) (Prince) **CHARLES** + **LAM** ("hit hard") + **B**(ishop)
 
2) Hidden in (*taking part in*) "immatur**E LIA**isons", Elia being Charles Lamb's nom de plume.