"Good King Wenceslas" is a popular Christmas carol, in which King Wenceslas is blessed for giving money to a poor peasant on St. Stephen's Day (26th December). Unusually for a Christmas carol, the words do not refer to the Nativity.
In the middle of the 19th century, John Mason Neale (Warden of Sackville College, East Grinstead, Sussex), a prolific reader and author came across a long narrative German poem about Wenceslas. A section in which the king walked out into the snow to rescue a poor swineherd particularly struck him. He adapted the poem into English and borrowed the tune to go with it from "Tempus Adest Floridum" ("Spring has unwrapped her flowers"), a 13th century spring carol. "Good King Wenceslas" was included in a 1853 publication Carols for Christmas-tide, by Neale and the Rev. Thomas Helmore (vice-Principal of St. Mark's College, Chelsea).
The arrangement generally used for this carol today first appeared as in Christmas Carols New and Old (1871) by Sir John Stainer and the Reverend H.R. Bramley. Apart From "Good King Wenceslas," their compilation also included Stainer's arrangements of what were to become the standard versions of "God Rest Ye Merry Gentlemen," "The First Nowell," "I Saw Three Ships" and "What Child Is This," among others.
The tale of King Wenceslas is based on a real person, Wenceslaus, the Duke of Bohemia, who in 935 gained control of Bohemia. Renowned for his piety, he took a vow of celibacy, founded many churches in Prague and elsewhere in the principality and spent much of his time in prayer and carrying out acts of piety. So great was his devotion that it is said he helped sow the corn and gather the grapes from which the bread and wine used at Mass was made. However, his brother Boleslaw and his supporters murdered the good Wenceslaus on his way to Mass by hacking him to death at the church door. His people were outraged and regarded the martyred Duke as a saint. Neale in his adaptation upgraded Wenceslas to a king.
The story inspired much more than a carol. Neale was so touched by the quality of mercy in the tale he read that he founded the Society of St. Margaret, which still offers care to the poor in their homes.