The turnout figure was given by the local police as vast crowds packed into a wide avenue running between the waterfront and the city’s towering Sagrada Familia basilica, which was once again closed to visitors.
Catalonia has been gripped by unrest since the October 14 Supreme Court verdict which unleashed a wave of huge demonstrations that quickly turned violent, with angry protesters hurling rocks and Molotov cocktails at riot police, who hit back with tear gas, foam rounds and rubber bullets.
The crisis began two years ago when the region staged a banned referendum on October 1 that was marred by police violence, then issued a short-lived declaration of independence, trigging Spain’s worst political crisis in decades.
Saturday’s rally was called by the ANC and Omnium Cultural, the region’s two biggest grassroots pro-independence groups that have organised some of the largest separatist protests in recent years.
Marching down the spacious boulevard, demonstrators held up banners reading “We won’t give in” and chanting “October 1, we won’t forgive, we won’t forget”.
As a police helicopter flew overhead, they broke into loud boos and whistling, an AFP correspondent said.
“I feel really angry,” said a 26-year-old computer technician from Tarragona called Marc, who did not give his surname and described the heavy prison sentences handed to nine separatist leaders as “totally over the top, inhuman, and shameful”.
“The violence doesn’t sit well with me but it’s normal to have a bit of upheaval like we’ve seen in Chile and Ecuador,” he said of a wave of mass protests in Latin America.