As protesting farmers breached barricades and changed their agreed route of a tractor rally to enter central Delhi on Republic Day, dozens of tractors rolled into the Red Fort.
Protesters were seen within the ramparts of the iconic Mughal-built monument, putting up yellow Sikh religious flags, waving sticks and shouting slogans.
The Red Fort complex was overrun with tractors and farmers holding flags within moments, with the police severely outnumbered. Some policemen were also manhandled by the protesters.
"Everybody come to Red Fort," shouted the farmers triumphantly against the backdrop of music blaring from tractors.
Farmers clashing with the police at the ITO intersection a few km away also headed to the Red Fort, as did thousands from several parts of Delhi.
In videos, farmers armed with sticks appeared to have a free run of the historic complex and some were seen breaking down security fencing. Reports suggested damage to the complex.
Soon, security and police personnel arrived to secure the Red Fort.
The farmers agreed to leave, saying they wanted to send a message to Prime Minister Narendra Modi and that message had been delivered.
However, even as security personnel removed protesters from the Red Fort, violence erupted again and there was a police lathi charge.
For nearly two months, the farmers had not been allowed to enter Delhi, and they had camped at several points just outside the city. The farmers are mostly from the neighboring states of Punjab, Haryana, Uttarakhand and Uttar Pradesh.
They are protesting against three central laws that the feel will harm their income and take away their guaranteed minimum earnings.
The government had offered to suspend the laws for 18 months while it held talks with the protest leaders, but the farmers refused to accept anything less than the laws repealed.
Union Minister of Tourism and Culture Prahlad Patel condemned the breach of the Red Fort and said it violated the symbol of the dignity of India's democracy.
"The Red Fort is a symbol of the dignity of our democracy. The farmers should have stayed away from it. I condemn the violation of this dignity. It is sad and unfortunate," Mr Patel said in a tweet.
The violence was condemned not just by the ruling BJP but also by other parties. Punjab Chief Minister Amarinder Singh of the Congress said: "Shocking scenes in Delhi. Violence by some elements is unacceptable. It'll negate goodwill generated by peaceful protests. Kisan leaders have disassociated themselves and suspended tractor rally. I urge all genuine farmers to vacate Delhi and return to the borders."