After the Mass celebrated in Saint Peters Basilica, Pope Benedict marked the feast of the Immaculate Conception, paying homage to the statue of Mary in Rome's historic Piazza di Spagna .
Thousands of Romans flocked to the square to greet the German pope, on his first 'pilgrimage' to the sculpture of the Virgin .
The tradition of the papal pilgrimage was brought back by his predecessor John Paul II more than 20 years ago .
"I deliver to the celestial mother of the Redeemer the anxieties and hopes of humanity," the 78-year-old pontiff said. He called on Mary to grace mankind with her spiritual presence "in every moment of our existence, above all during moments of darkness and trials." The statue of the Virgin Mary stands on a column in the northern section of the piazza, just around the corner from the famed Spanish Steps known to all tourists .
The column was erected by Pope Pius IX in 1854 after he declared the dogma of her immaculate conception, meaning that Jesus' mother was conceived without the stain of original sin .