One June evening in 1865 William was walking along Whitechapel Road in East London when he came upon an open-air gospel meeting outside the ‘Blind Beggar’ public house. An invitation was given to anyone willing to speak and he accepted.

William made such an impression that a few days later some representatives of the group, the Christian Revival Association, invited him to lead a campaign in place of a preacher who had fallen ill.

The revival campaign was being held in a tent on a disused Quaker burial ground at Mile End. The tent reeked of unwashed humanity and naphtha lamps but week after week many East Enders responded to William’s preaching and were converted.

East London at this time was an over-crowded, poverty-stricken, crime-ridden area. Drunkenness was common, disease was rife and starvation was not unknown. It was to these people that William now dedicated his life. Coming home to Catherine one evening he declared, ‘I have found my destiny!’

The original aim was to direct the new converts to the local churches and chapels rather than start another denomination. However, many would not go and those who did often found themselves unwelcome. The work, or possibly the man, was attracting a following and creating a movement.

When the tent became unusable due to autumn gales ‘The East London Christian Mission’ (as it soon came to be known) moved to a dance-hall, which could be fitted with seats only after the dancing finished early on Sunday mornings. In addition there were regular open-air processions and meetings.

Soon other mission stations were opened in the most unlikely places - a coffee shop, a wool store, an old furniture store, a disused chapel, a stable, a skittle alley and the once infamous Effingham Theatre. The former ‘Eastern Star’ public house in Whitechapel Road became the first headquarters.

By 1868 the Mission had eleven stations in the East End. As well as preaching there were soup kitchens, cheap food sales, clothing distribution and visiting of the sick. That year the Mission began the publication of its own magazine, The East London Evangelist.

By 1869 the work had begun to spread to other parts of London so ‘The East London Christian Mission’ became ‘The Christian Mission’.

In 1870 an annual conference was initiated and a new headquarters was opened at ‘The People’s Market’ (renamed 'People's Mission Hall'), Whitechapel.

In 1875 the Rules and Doctrines of the Christian Mission was published clearly reflecting William’s Methodist roots. One important principle (which did not conform to Methodist practice!) allowed women to share fully in the leadership and work of the Mission. At first the Mission was governed by a system of committees and conferences, but this proved a hindrance to the rapid development of the young movement. At the suggestion of a group of missioners, the Conference abolished itself in July 1877, and William was placed in sole command.

While William concentrated on this work, Catherine preached to people higher up the social ladder, partly for their own good, and partly to gain financial assistance for the Mission. The work was always in need of money. The Mission members were too poor to support it, so outside benefactors were vital. Henry Reed, a wealthy retired grazier who had returned from Tasmania, set up a trust to support the Booths. Because of this William never drew any salary from the Mission's funds.

By 1878 the Christian Mission had 30 stations and 36 missioners in locations across the United Kingdom. Dramatic growth was just around the corner. It came with the adoption of new practices and the change of name to The Salvation Army.