Didn't he get the England job on the back of doing well at Middlesbrough?
A quick wiki search:
Won the league cup.
Qualified for Europe for the first time in their history.
Reached the last 16 of the UEFA cup.
Finished 7th in EPL - best finish since 1975.
Reached UEFA cup final - first English manager to reach the final since 1984.
A couple of FA cup semifinals.
Failure?