For Grazyna Klimowicz, the emotions were extreme — deep pain over the loss of John Paul II (search) and joy that his faithful servant, Pope Benedict XVI (search), was chosen to guide the world's Roman Catholics.

The Polish tour guide was among some 400,000 people who packed St. Peter's Square (search) and surrounding streets for Benedict's installation Mass Sunday, their emotions turning to a pontiff who is already winning hearts for his gentle manner and long service to his much-loved predecessor.

"There's pain on one side, and joy on the other side because all of the world has a new pope with a deep soul, a beautiful soul," said Klimowicz, 52, who led pilgrims to visit the tomb of Polish-born John Paul and to witness Benedict's installation.

"He loved our pope. So I think this papacy will be good and I hope it will be long."

The faithful began taking up spots before dawn on the cobblestones of St. Peter's Square. By the time the service began, they were craning their necks for a glimpse of the German-born pontiff in his golden vestments as he formally took charge of the world's 1.1 billion Catholics.

After the nearly three-hour Mass, people stood and waved as Benedict blessed the crowd while riding through the square in a white, open-topped jeep-like vehicle surrounded by security guards.

Those nearby reached out toward him and snapped pictures. Parents lifted children on their shoulders, others scrambled onto the square's fountains for a glimpse, and some chanted the pope's name in Italian — "Benedetto!" — and clapped rhythmically.

"He seems really nervous," muttered an elderly Italian man as Benedict opening his homily in a tentative voice, coughing at times.

But as Benedict went on, his voice grew firmer. And many said they liked what they heard.

"I am very favorably impressed by what he said," said Angelo Madonini, a 30-year-old Italian lawyer seeking refuge from the sun under the square's colonnades during the Mass.

"The pope said the church is alive, young, vital. He's showing that what you read in the newspapers about the church being dead isn't true."

Pilgrims waved flags from around the world — the black, gold and red of the pope's native Germany, and even more often the red-and-white Polish banner.

"We still remember John Paul and we love him," said Wojtek Lech, 24, an economics student from Rzeszow, Poland. "Everyone in Poland feels the same for the pope — our pope."

Groups from Benedict's home region of Bavaria showed up in traditional attire, the men in lederhosen and women in traditional dresses known as dirndls.

"It's beautiful to be here," said Veronica Vutz, 32, from Berchtesgaden, Germany, wearing a tight-fitting brown bodice and aproned green skirt. "We came here just for this."

Prelates in crimson caps and Swiss Guards in their gaily colored uniforms and red-plumed helmets formed the backdrop.

Many people bought postcards and other souvenirs of the new pope and the old pope as they trickled out of the square.

Outside the square, Benedict's nationality was acknowledged in a crude manner: Someone had drawn an Adolf Hitler-style mustache and a swastika armband on a poster of Benedict.

The pope has acknowledged being a member of Hitler Youth as a teenager and was drafted to serve in the German army. He says he was forced into participating.