Eurovision removed its national-language performance rule in 1999.
The rule had required contestants to sing in one of their country’s official languages for much of Eurovision’s history. It was relaxed temporarily in the 1973 and 1974 contests, restored in 1977, and then abandoned permanently from the 1999 competition onward.
The 1999 final was held in Jerusalem, where Sweden’s Charlotte Nilsson won with “Take Me to Your Heaven.” The new freedom allowed countries to choose English or another language for strategic and artistic reasons. English quickly became dominant, although many later entries continued to use national languages or combine several languages.
The rule change is often linked with the growing international reach of English-language pop, but it did not make English mandatory. Eurovision has never required every song to use English; the regulation simply stopped restricting contestants to national languages.