Conversation so far:
When was Imran Khan captain?
In 1982, the thirty-year-old Imran Khan took over the captaincy of the Pakistan cricket team from Javed Miandad.
How long was Imran Khan captain?
Imran Khan served as the team's captain intermittently between 1982 and 1992

Question: Who was his co captain?
Self-contained rewrite: Who was Imran Khan's co captain?