An estimated 270,000 people greeted Pope Benedict XVI in a rain-drenched Warsaw square Friday at the spot where his predecessor, John Paul II, inspired Poland's Solidarity movement against communist rule in a historic 1979 visit. People lined the street to wave and cheer as Benedict's "popemobile" passed, and church bells pealed. Police spokesman Pavel Biedziak provided the crowd estimate. Spectators stood resolutely in ponchos and under umbrellas, filling vast Pilsudski Square before the (0730 GMT) 9:30 a.m. start, determined to see Benedict pay tribute to his friend and mentor - a main theme of his trip to Poland. The choice of site for the Mass recalled John Paul II's bold call to "renew the face of this land" at the square, then called Victory Square, during his triumphant first visit to his native land after being elected pope. His appearance challenged the atheist communist authorities and is credited by Solidarity founder Lech Walesa with energizing the emerging trade union resistance to Soviet-backed communist rule, which collapsed in 1989-90. The crowd was less than in 1979, when some 300,000 people jammed the square, with some 750,000 in the surrounding streets. White and yellow Vatican flags festooned lampposts, and Benedict's picture stood in apartment windows; one window on Mazowiecka Street had pictures of both Benedict and John Paul. Benedict was to speak from a 4-meter (17-foot) platform topped by a 25-meter (82-foot) cross. "Today, the feeling is more spontaneous - in 1979, we still were under a different system, we were under a regime and people came because they wanted this meeting with the pope to bring fruit, and it did, " Barbara Kamela, 60, a retired bookkeeper who attended the 1979 Mass. "John Paul II was dearer to us, because he was our brother," she said. "This pope is visibly trying to be close to us, we have a strong impression from him and I came to this Mass to be near him." The Mass is the highlight of the second day of a four-day trip which will include Benedict's trip to the Auschwitz-Birkenau concentration camp, a visit heavy with significance for Catholic-Jewish relations, a favorite cause of both Benedict and John Paul.