Who is the youngest person ever to have won the Eurovision Song Contest?

Explanation

Sandra Kim from Belgium was only 13 years old when she won with the song "J'aime la vie" in 1986. In the song, she claimed to be 15, but after the final, her young age of 13 was revealed. The then runner-up Switzerland tried to have her disqualified, but to no avail. Later, a minimum age of 16 has been introduced, so Sandra Kim's record can never be broken. The final was held in Bergen, Norway, with, for the first time, royalty present (the Norwegian royal family).