Sex, gender and sexuality have always been the subject of lively debates within and around the military — from the age-old problem of the on and off-duty sexual behaviour of servicemen to the more recent process of creating a place for women as front-line fighters. In recent years a spate of scandals has challenged the reputation and operation of the armed services. But there is another side that needs to be taken into account — increasingly, very public action is being taken in support of lesbian, gay, bisexual, transgender and intersex (LGBTI) personnel against those accused of sexism and homophobia. This article seeks to place these developments in an historical context, focussing on homosexuality during World War II. Drawing on the memories and memoirs of homosexual men as well as archival records of the responses of Army officials and other servicemen who encountered same-sex behaviour, we explore a range of homosexual behaviours and identities present in the armed services. We are particularly interested in how a vilified, marginalised and criminalised minority made lives for themselves in the forces and, for all the risks and penalties they faced, the fact that these lives were characterised by pleasure and conviviality as much as by fear and victimisation. Three forces were at work, each shaping the homosexual sub-cultures in their own ways — the commanding echelons, homosexual men, and the broader mass of service personnel.