"The parliament stood proudly, Turkey stood proudly, lawmakers stood proudly, people in this square have stood proudly, and democracy won!" CHP leader Kemal Kilicdaroglu told the crowd, who had listened to the last post and the national anthem in honour of the victims of the coup attempt.
The ruling AKP officially supported the rally but it was very different to last week's assemblies, where President Recep Tayyip Erdogan's speeches were shown on giant screens and government support was much in evidence.
Sunday's crowd carried portraits of Turkey's founder, Mustafa Kemal Atatürk, the hero of the secular camp along with the Turkish flags that have become even more ubiquitous than before the coup.
Like many on the square Sunday, Hussein, a young man shading himself from the sun with an Atatürk portrait, hadn't been to the previous week's rallies, where crowds occupied public places in response to Erdogan's appeal to prevent a new coup attempt.
He insisted that it is the secular camp, not the AKP, that is responsible for Turkey's democracy.
"We are here to capture democracy and secularism in Turkey," he said. "We supported and established democracy in Turkey, not the other people."
With 50,000 people fired or jailed since the coup and Amnesty International claiming to have reports of the torture of detainees, many of Sunday's demonstrators seemed to be there partly to ensure the crackdown does not take in Erdogan's secular opponents.
"Sometimes we believe that the government tries to take advantage of this for antidemocratic rule and this is the reason I wanted to come here and show that I am against this coup d'état but also on the other side I am against the ruling party," said Hayri, an older man, who also blames world leaders for the crisis that has hit Turkey and the surrounding region.
"I think the world should understand that they shouldn't play with Islam, which they did as a mistake in Syria," he went on. "All that is going on, from Munich to here, is because of this dirty game and Turkey is also partly responsible for this dirty game, with Saudi Arabia and Qatar."
This is a "very important moment for democracy in Turkey", he believes.
Refugees from other conflicts were also on Sunday's demonstration - a group of Afghan Hazaras, dismayed at the weekend's attack on a protest in Kabul, wanted to show solidarity with the nation where they had taken refuge.
"I am here to see the new face of democracy," said Abdurazzak, a Libyan. "We are supporting Turkish people who face this army who want to take authority by force because in Libya we are still suffering from this. We are still fighting to get our democracy."
Although the opposition has called the rally, it represented all Turkish, he felt.
"Here you feel that you are Turkish. I am from Libya but I feel Turkish."
The demonstration would be one of the most important in Turkish history, according to political scientist Behül Özkan, speaking before it had officially started.
The secular camp counts millions who cannot be ignored, he pointed out. "These people feel threatened because for the past one week, although the coup was initiated by an Islamist group, mainly established in the army, the Gülenists, against an Islamist government ... the supporters of the government turned the protests against this coup into a showdown of Islamism. They used Islamic symbols, Islamic slogans and they started throwing Islamic symbols in secular neighbourhoods. And the exact word is, the secular people feel trapped."
Erdogan on Monday invited CHP leader Kilicdaroglu, Devlet Bahceli of the right-wing, secular Nationalist Action Party and Prime Minister Binali Yildirim to meet him to discuss the post-coup situation.
But, despite the speeches, the flags and the professions of patriotism, beneath the unity there is still distrust in the secular camp.