sentences:  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.