Vatican City ? Pilgrims began arriving in Rome on Saturday to mark the first anniversary of Pope John Paul II’s death, praying by his tomb and preparing for an evening vigil today in St. Peter’s Square to commemorate the exact moment of his passing.

The Polish Embassy to the Holy See said it expected some 10,000 citizens of John Paul’s homeland to participate in the Vatican’s anniversary commemorations, which also include a Mass on Monday celebrated by Pope Benedict XVI. The city said it was expecting between 100,000 and 150,000 pilgrims.

On Saturday, groups of pilgrims milled about the square, some toting the flags and banners of Solidarity, Poland’s pro-democracy trade union. John Paul was a strong supporter of Solidarity and is credited with helping to overthrow communism in Poland in 1989.

Other pilgrims visited John Paul’s simple white marble tomb in a grotto beneath St. Peter’s Basilica, kneeling in prayer and tossing flowers and notes onto his grave.

“It is my biggest dream in life to visit his tomb,” said Henry Adamczyk, 55, of Lubin, Poland. “I was happy to hear he died so he can go and visit his father in heaven.”

John Paul died April 2 at 9:37 p.m. in his apartment in the Vatican’s Apostolic Palace, surrounded by Polish prelates and nuns and his doctors. The cause of death was blood poisoning, as well as kidney and heart failure brought on by a urinary tract infection.

Polish pilgrims, wearing scarves and holding flags of the Solidarity pro-democracy movement, arrive in St. Peter's Square at the Vatican on Saturday, a day before the one-year anniversary of the death of Polish-born Pope John Paul II. Pilgrims have begun arriving in Rome to mark the first anniversary of John Paul II's death, praying by his tomb and preparing for an evening vigil in St. Peter's Square today to commemorate the exact time of his passing. In the background is St. Peter's Basilica.

He had suffered for years from Parkinson’s disease, and by the end of his life was unable to speak to the faithful, managing only to bless them weakly with his hand.

Today’s anniversary vigil, to be led by Cardinal Camillo Ruini, is likely to recall the scenes in St. Peter’s in the days and weeks before John Paul’s death, during which tens of thousands of people lit candles and prayed silently underneath the papal apartment windows.

Ruini, the vicar for Rome, is expected to lead the faithful in recitation of the Rosary prayer, and Benedict is expected to address the crowd near the time of John Paul’s death.

On Monday, Benedict celebrates a Mass inside the Basilica that is expected to be attended by John Paul’s longtime private secretary, the newly elevated Cardinal Stanislaw Dziwisz, archbishop of Krakow.

In Poland, John Paul will be remembered with Masses and other ceremonies throughout the country, including in Wadowice – the small southern town where he was born Karol Wojtyla in 1920 – and in Krakow, where he served as priest and archbishop. Benedict will address crowds in Krakow by video hookup.