Who is William Bush from Commodore Hornblower and what is their importance?

Bush is one of Hornblower's long-time friends. He has a wooden leg, having lost a leg under the command of Hornblower, and his service is nearly perfect, though he isn't overly imaginative. Bush recognizes his strengths as well as his limitations, however, and because of this he is the perfect subordinate to Hornblower, who relies upon Bush absolutely and continually. Bush commands Nonsuch, and when Hornblower is debilitated by typhus, Bush assumes command of the entire squadron and leads it home to England.