The British assembled two divisions from their
Bengal Army commanded by Sir Harry Fane and another force of a single division from
Bombay under the command of
Sir John Keane. The Bombay force, numbering some 6,000 men, would sail by sea and land near the
Indus river and then march into Afghanistan to join Fane's forces. The size of the invasion force was reduced from three divisions to two because there was no longer any prospect of confronting Persian and Russian forces. The second Bengal division which was originally supposed to take part in the invasion was now relegated as a reserve force and would remain in India. Following the agreement between Ranjit Singh and British viceroy Lord Auckland to restore Shah Shoja to the Afghan throne in Kabul, the British army marched towards Afghanistan from the south whereas Ranjit Singh's army marched through the Khyber Pass, which concluded with the participation in the victory parade in Kabul. The
Bengal Army, which now numbered some 8,500 men, would march inland towards
Quetta after assembling in
Ferozpur. In Quetta, it would link up with the Bombay Army and then invade Afghanistan. The Bengal Army would also be accompanied by 6,000 men led by Shuja Shah Durrani. The men under Durrani's command were Afghan exiles who believed that he was the rightful ruler of Afghanistan. The total size of the invasion force now numbered some 20,500 men. Sir Harry Fane refused to take part in the invasion because the Russians and Persians had abandoned the siege of Herat and the pretext for the invasion of Afghanistan was no longer there, and so the command of the invasion force passed to Sir John Keane. The Bombay Army landed near the Indus river in December 1838 and continued to march until it met with the Bengal Army in
Quetta. The Invasion force was short on supplies due to taking the longer southern route into Afghanistan, and also because many British supply convoys were lost to harassing attacks by tribesman in
Baluchistan. Many soldiers were starving and there was only enough water for the men, which caused many horses to die. However, Sir John Keane pressed on with the advance into Afghanistan through the Bolan and Kojuk passes. His forces marched 147 miles into Afghanistan and reached
Kandahar on 4 May 1839. The local city leaders escaped to Western Afghanistan and the city was captured without the British firing a shot. The army's next objective was the fortress city of Ghazni as it commanded the trade routes and roads leading into Kabul. Before a final advance towards Kabul could be made, Ghazni had to be captured. ==Battle for the city==