He called for an end to Islamophobia and persecution of all minorities. And he assured the audience that Jews were among friends in Britain in the fight against antisemitism: "I have received letters of support from national leaders and ordinary men and women in the street. We are not alone."
The demonstration was organised by the Campaign Against Antisemitism, in response to the rise in attacks against Jews across Europe and the UK during the Gaza conflict and a perceived lack of action from the communal leadership.
CAA spokesperson Jonathan Sacerdoti said: "We are united with our dissatisfaction that Jews are not being protected sufficiently from antisemitic attacks. It is time we say 'enough'."
Maajid Nawaz, chairman of the anti-extremist organisation, the Quilliam Foundation, told the crowd: "Do not hide your ethnicity, your religion or your culture, and if I have anything to do with it, in this country you will be safe."
Mr Nawaz, a Muslim, called for more "cross-religious ties in the fight against antisemitism".
Board of Deputies president Vivian Wineman and senior vice president Laura Marks were booed as they took to the stage, with some of the crowd calling out, "you need to do more" and "resign".
The Board has been criticised for failing to provide leadership, and over last week's joint statement with the Muslim Council of Britain.
Ruth Gordon, from Stanmore, said she had come to the rally because she was concerned for the future and safety of her grandchildren.
Edwin Shomir, a 25-year-old property manager from Hendon, said the rise in antisemitism had only strengthened his Jewish identity. "I'm not covering my kippah. I'm not wearing a hat. I've got nothing to hide. But yes, the situation is scary," he said.
Eighty-year-old Sheila Levet, who attended with three friends, praised the Board's attempt to forge closer interfaith relations.
"I think the joint statement they did with the MCB was very brave. For Muslims to align with the Jewish community is great . That kind of interfaith work is important," she said.
The CAA said more than 4,500 people attended the rally, a figure confirmed by police on the day.
"It was a lot more than expected and the fact we put the rally together in such a short time shows what the community can achieve," a spokesman said.
