Today (December 26th) is the feast day of St Stephen, who is the earliest Christian martyr as far as is known. His martyrdom is recorded in the Acts of the Apostles, which tells how he was stoned to death.
The day is also famous for the Christmas carol Good King Wenceslas, the action of which takes place on the feast of Stephen. This was penned by John Mason Neale in 1853, using a traditional tune. Critics said it would never catch on.
The subject of the carol is Duke Wenceslas/Wenceslaus/Vaclav of Bohemia. This character lived in the 10th Century and is regarded as a saint in the Catholic Church. He was murdered. After his death the Holy Roman Emperor Otto I conferred the title of king on him posthumously.
When Bohemia (in the modern Czech Republic) is in danger, it is said that the statue of the king in Wenceslas Square will come to life. He will rouse a host of sleeping warriors in the mountain of Blanik. They will cross Charles Bridge, where his horse will stumble and he will then find the sword Bruncvik. He will then defeat the enemies of his country.