Mindaugas, the first and only King of Lithuania, was crowned on 6 July 1253.
After Mindaugas accepted Christianity in 1251, the Grand Duchy of Lithuania was proclaimed a Catholic Kingdom of Lithuania by a papal bull written by Pope Innocent IV in Milan. This way, Grand Duke Mindaugas of Lithuania, who later became King of Lithuania, made a step towards international recognition of Lithuania in Europe. However, the coronation of King Mindaugas and Duchess Morta was an even more significant achievement for Lithuania in that a papal decree established the Diocese of Lithuania, thus concurrently recognising the state of Lithuania.
On 25 October 1990, the Supreme Council – Reconstituent Seimas of the Republic of Lithuania passed the Law on Public Holidays declaring 6 July, the day of the coronation of King Mindaugas, to be a public holiday.