During the International Congress held at the Crystal Palace, Sydenham, London, in 1904, Commissioner Henry T. Howard voiced what he saw as the young Salvation Army's need for leaders inspired with the aggressive spirit of Salvationism. William Booth took up the idea and the International Staff Training Lodge was opened at Clapton on 11 May 1905.

Following the purchase of The Cedars in Sydenham, the International Staff College started in 1950. Four years later it became the International College for Officers (ICO), with General Albert Orsborn declaring it to be ‘an investment in the great intangibles without which our cogs and wheels would soon be rusty and dead’.

To date, more than 5,000 officers have attended the ICO, which Commissioner Alfred Gilliard (Principal 1954-60) described as ‘one of the Army's most brilliant long-term investments’.

In March 2014, the ICO was relocated to the newly refurbished Sunbury Court Conference Centre.