However, they lacked the heavy artillery needed to assault the fort, and moved instead to join the rebels who had rallied to the nominal leadership of Emperor Bahadur Shah Zafar in Delhi.

This allowed the British to establish tenuous communications from east to west across the territories of Northern India previously in rebel hands, and to concentrate troops for the vital Relief of Lucknow.

They subsequently moved to Delhi, where they called on more sepoys to join them, and for the Emperor Bahadur Shah Zafar to lead a nationwide rebellion.

The British were warned by telegraph messages sent before Delhi was captured, but Indian messengers and other travellers also rapidly spread excited versions of the events.

His first instinct was to withdraw the East India Company's administrators and their families into the Agra Fort but was persuaded by others including Robert Drummond, the chief magistrate, that while the sepoys' loyalty was suspect, the general population of the province was loyal to the British.

This force consisted largely of the brigades of Bengal Native troops which had been stationed at Nimach and Nasirabad and which had joined the rebellion.

[3] Colvin belatedly gave permission for the 6,000 British civilians and their families and dependents (including many who had already fled the disturbances in the countryside) to move from the vulnerable civil cantonment into the fort.

The infantry were still dressed in thick scarlet uniforms, and the movement did not start until 11:00 am, in the full heat of the day at the height of summer.

The British were able to send a dispatch to Lord Canning, the Governor General of Bengal, shortly after the debacle at Sacheta and the uprising within the city.

[2]: 160  Colvin himself was increasingly incapable of managing the situation, ignoring pressing matters to deal with routine correspondence or irrelevancies.

The strongest column, which numbered 750 British and 1,900 Sikh and Punjabi soldiers, consisted of: the 9th Lancers, detachments from the 1st, 2nd and 5th Punjab Cavalry (a squadron of each), Hodson's Horse (irregular levies), the 8th and 75th regiments, the 2nd and 4th Punjab Infantry regiments, two troops of Bengal Horse Artillery and a field battery of Bengal Artillery, and 200 Sappers and Miners.

The column moved along the Grand Trunk Road, fighting a sharp action against rebels at Bulandshahr[5] and taking indiscriminate punitive measures against several Indian villages.

[2]: 324  Many civilians had celebrated the recapture of Delhi by going sightseeing at the Taj Mahal, and suddenly fled back to Agra in disorder.

By contrast many of the civilians were fashionably and smartly dressed, and the soldiers of the garrison were still splendid in scarlet uniforms with pipeclayed white belts.

[1]: 43 Having recovered from their earlier state of panic, the senior officers of the garrison now assured Greathed that on news of his approach, the rebels had retreated across the Khara Naddi, a stream 9 miles (14 km) distant.

They did not post pickets or sentries, even though there were fields of bajra, a tall millet-like crop which hid any approaching enemy from view, in front of the parade ground.

The column's baggage animals with tents and supplies were still arriving, and many of the occupants of the fort and inhabitants of the city went to view Greathed's troops.

A group of jugglers approached some of the 9th Lancers and Punjab Cavalry before suddenly revealing themselves to be Muslim fanatics, drawing swords and slashing at the cavalrymen.

Lieutenant Colonel Cotton, of the garrison, was supposedly senior to Greathed and after some delay while he was briefed on the situation, the advance began, the entire force in line with skirmishers in front.

Although Greathed's cavalry cut down few of the fleeing rebels, other eyewitness accounts maintained that the ground in front of the British camp was thickly strewn with dead bodies.

After the victory, the commanders of the garrison reverted to their previous state of panic, and wanted Greathed to remain in the area to protect Agra against rebels from Gwalior.

He was also persuaded by a note received while at Bulandshahr from General Henry Havelock, who said that he was on his way to relieve Lucknow and urgently needed reinforcements and transport.