Founded in 1966, the Language Freedom Movement (Irish: Gluaiseacht Saoirse Teanga) was a political organisation opposed to the state-sponsored revival of the Irish language in the Republic of Ireland, which had the backing of several notable Irish-speaking writers including Séamus Ó Grianna ("Máire") and John B. Keane.
At the time the Movement was formed, if a student failed the Irish paper in their Leaving Certificate they were deemed to have failed the whole exam. This requirement was abolished in 1973, although students are still obliged to study Irish as part of the Leaving Certificate programme, and a pass is required for Irish students entering certain Irish universities (but not for foreign students). In 1974 Irish was removed as a requirement for entry to the civil service.
Significant changes in the Leaving Certificate maths curriculum were reflected in two new textbooks produced by the Irish Christian Brothers. However, material for the new honours (higher-level) syllabus was offered only in a government-subsidised book in Irish, while the pass (lower-level) material was published in English. The situation continued for several years, until affordable alternative textbooks eventually became available.
The Movement organised a meeting in the Mansion House, Dublin on 21 September 1966. About 2000 people turned up, though most of them seemed opposed to the Movement. Opponents taunted the organisers by waving Union Jacks at them. One person seized an Irish Tricolour from the table used by the movement, shouting that the flag should not be displayed at such a meeting. A fight involving ten men broke out and calm was only restored when the LFM agreed to four of their opponents speaking at the meeting.
Gardaí were present. At the request of the organisers, Patrick Byrne TD had asked the Garda Commissioner to ensure law and order prevailed.