Pope John Paul has appointed 31 new cardinals, stamping his authority on the group that will elect his successor when he dies.
The Pope has reigned for 25 years
The name of one of the cardinals is being kept secret, a formula used when an announcement could endanger him - for example in a country where the church faces oppression.
All but a handful of the new cardinals are under 80, so would be eligible to vote on the pontiff's successor.
The pontiff has come under increasing pressure to get the papal electoral college in order following the death and ageing of some of its members, says BBC correspondent in Rome David Willey.
The appointments were announced by the Pope to pilgrims gathered in St Peter's Square.
Correspondents say that with many coming from the developing world, the announcement will add to speculation that the next Pope could come from there.
The list did not include Archbishop Sean
Patrick O'Malley, recently called to head the Boston archdiocese
in the wake of a child sex scandal.
He had been widely expected
to be made a cardinal.
The cardinals will get their red hats at a special service, known as
a consistory, to be held on 21 October, at the end of
ceremonies marking the 25th anniversary of the pontiff's election.
The new cardinals include top Vatican officials - such as the Vatican's foreign minister - as well
as prelates from Italy, Nigeria, France, Spain, Brazil, Ghana,
India, Croatia, Guatemala, Hungary, Canada, Switzerland,
Belgium, the Czech Republic and the pontiff's native Poland.
It is the ninth time the frail 83-year-old Pope has named new cardinals and is perhaps his last chance to influence the group of men that will choose the next
leader of the world's one billion Catholics.