One of my favorite Christmas Carols. The first lines make that brief mention of the "feast of Stephen" (today), but I haven't been able to find anything in reference to St. Stephen in relation to St. Wenceslaus, except for this passage:
The words to the carol "Good King Wenceslas" were written by John Mason Neale and published in 1853, the music originates in Finland 300 years earlier. This Christmas carol is unusual as there is no reference in the lyrics to the nativity. Good King Wenceslas was the king of Bohemia in the 10th century. Good King Wenceslas was a Catholic and was martyred following his assassination by his brother Boleslaw and his supporters, his Saint's Day is September 28th, and he is the Patron Saint of the Czech Republic. St. Stephen's feast day was celebrated on 26th December which is why this song is sung as a Christmas carol.
Source of the above paragraph
Good King Wenceslaus looked out on the feast of Stephen.
When the snow lay round about, deep and crisp and even.
Brightly shone the moon that night, though the frost was cruel,
When a poor man came in sight, gathering winter fuel.
Hither page and stand by me if thou knowst it telling
Yonder peasant, who is he, where and what his dwelling?
Sire, he lives a good league hence, underneath the mountain,
Right against the forest fence, by Saint Agnes' fountain.
Bring me flesh and bring me wine, bring me pinelogs hither
Thou and I will see him dine when we bear them thither
Page and monarch forth they went, forth they went together
Through the rude winds wild lament, and the bitter weather.
Sire the night is darker now, and the wind blows stronger
Fails my heart I know now how, I can go no longer.
Mark my footsteps my good page, tread thou in them boldly
Thou shalt find the winter's rage freeze thy blood less coldly.
In his master's steps he trod where the snow lay dinted
Heat was in the very sod which the saint had printed
Therefore Christian men be sure, wealth or rank possessing,
Ye who now will bless the poor, shall yourselves find blessing.