The custom to light fires around Midsummer and the summer solstice dates back to ancient times: The solstice bonfires, or St. John's Eve Fires, were mentioned for the first time in written documents already in the 12th century. In the 18th century, however, that tradition was reinterpreted. In 1796, the Tyrolean representatives - in view of the imminent threat of invasion by Napoleon - pledged their troth to the Sacred Heart of Jesus if they would be saved.

After the unexpected victory of the Tyrolean troops over the French forces, they lit huge fires on the mountains to thank God and to honour the Sacred Heart. Andreas Hofer renewed the vow before the Bergisel battle against the French and the Bavarians, in order to unify the fighters.

They won once again - and that made the Sacred Heart Sunday a significant holiday. Still today, it is celebrated every year on the third Sunday after Whitsunday. The Sacred Heart Fires light up the South Tyrolean sky. Also in North Tyrol, they are still kept alive. Huge figures are made out of fire, mainly religious symbols such as crosses, the Sacred Heart or the inscription INRI or IHS.