The suppression of the student-led movement had a profound affect on Hong Kong, which in 1989 was just eight years away from reverting to Chinese sovereignty after more than a century of British rule.

“I’m Chinese,” said H. C. Tsui, 76, a retired middle school headmaster and native Hong Konger who has attended most vigils in the past quarter-century. He was sitting with many other elderly people on bleachers on the perimeter of the athletic fields, where organizers estimated 125,000 people gathered this year. (The police put the figure at 21,800.)

“I have to remember those who have been persecuted and assaulted during the 6-4 movement,” Mr. Tsui said, using a term to describe the date of the protests. “That is my job, my responsibility. I must be here.”

Many young people in this city of more than seven million do not agree with Mr. Tsui’s view of himself. Dismayed by the continued autocratic rule of the Communist Party in Beijing, and the threat it poses to Hong Kong’s liberties, they increasingly identify themselves with their city, not China.