The 1967 Sexual Offences Act partially decriminalised sex between men but made no reference at all to lesbian sex. Lesbian sex had never been taken seriously enough (some even doubted the possibility of it) for society to make laws against it.

Consequently this milestone in 'gay' history was not a key moment for gay women - they found themselves undermined, but never outlawed, by the state.

The invisibility of lesbianism was ended by the rise of lesbian feminism as a radical political movement in the 60s and 70s.

Lesbian feminists suggested there were only two ways a woman could genuinely escape male control - the first was to embrace lesbianism; the second was to overthrow the social order that automatically places men at the top of the social hierarchy.

The Remember 1967 series consists of six digital billboards created to mark the 50th anniversary of the Sexual Offences Act 1967.

Remember 1967 echoes demands made by activists in the 1960s that still warrant action today.