Farmers were seen shouting slogans at the iconic Red Fort.
Here are 10 developments in this big story:
Visuals from the Red Fort showed farmers hoisting a sacred flag of Sikhs at a second flagpole. Thousands of others, waving the national flag, stood at the huge gates of the fort. The police were seen trying to control the crowd in vain.
"We came here to deliver a message to the Modi government, our job is done. We will go back now," one of the farmers told NDTV at the Red Fort. "We managed to reach the fort even though they tried to stop us. We will not stop till we reach our goal -- the repeal of the three farm laws," another farmer said.
Farmers were given police permission to hold the rally on the periphery of the city after a court battle. It was to be a peaceful rally, with 60-odd km routes in three parts of the city. But last evening, one of the participants -- the Kisan Mazdoor Sangharsh Committee -- refused to stick to the designated route.
Even the time for start of the rally, 10 am, was tweaked. The rally -- to be held over 60-odd-km stretches near the Singhu, Tikri and Ghazipur borders -- was expected to enter the city only after the traditional Republic Day parade ended around 11.30 am.
But by 8 am, even before the parade started, crowds swelled at the borders and thousands entered the national capital on foot. Dramatic visuals showed farmers breaching barriers at the Singhu border, the epicentre of protests against the farm laws that started on November 26.
As Delhi Police appealed to the protesters to maintain calm, in central Delhi's ITO, a police bus was hijacked. A clip from Akshardham showed policemen on an overbridge, firing tear gas shells on the protesters standing below. A bus was vandalised. The Delhi Metro Rail Corporation shut the gates at several metro stations. In Nagloi, the police had to fire teargas shells to disperse protesters.
"Violence is not the solution to any problem. If anyone gets hurt, our nation will suffer. Take back the anti-farmer law for the benefit of the country!" Congress's Rahul Gandhi tweeted as farmer union leaders appealed for calm.
The farmers' body Samyukta Kisan Morcha said in a statement: "Despite all our efforts, some organisations and individuals have violated the route and indulged in condemnable acts. Anti-social elements had infiltrated the otherwise peaceful movement. We have always held that peace is our biggest strength, and that any violation would hurt the movement. The long struggle for more than 6 months now, and more than 60 days of protest at Delhi borders also seemed to have led to this situation."
The Centre had opposed the rally in the Supreme Court, contending that its timing will make it "an embarrassment to the nation". But the court, which earlier upheld the farmers' right to hold peaceful protests, had handed over the matter to the Delhi Police, saying it involved law and order.
Eleven rounds of talks have been held between the farmers and the government but there been no breakthrough. The farmers have turned down the Centre's last offer to put the laws on hold for 18 months while a special committee conducts negotiations.