He said Labour should be proud of its achievements, and urged the party to continue its reforms. Nick Robinson reports.
He proffered advice on tackling the myriad challenges ahead for both the UK and for his party in a changing world.
Rory Cellan-Jones looks at Mr Blair's original ambitions for Britain - and what he has actually achieved.
Speaking beforehand, Peter Mandelson said Gordon Brown "never fully reconciled" himself to Mr Blair becoming leader instead of him.