They were discovered in 1890 by Aleksander Brückner, in the form of parchment pieces cut into reinforcing strips, inside the binding of a Latin language codex, which contained the Acts of the Apostles and the Apocalypse.

In 1934, facsimiles of the text were published by the Polish Academy of Learning, and in 2009, new, full edition of the sermons was issued, prepared by professor Paweł Stępień.

Even though Aleksander Brückner claimed that the text was originally housed at the Holy Cross Monastery, this hypothesis has been criticized by some scholars.

According to historian Władysław Semkowicz, the codex, already strengthened with strips of parchment, was delivered to a Benedictine monastery at Leżajsk, around 1459.

At that time, the monks of this monastery were of Czech and German origin, who either did not speak Polish, or spoke it poorly and were unable to write down the complicated text.

Some time in the 15th century, the sermons were cut into strips, which were used to strengthen the binding of a Latin language codex.

This practice was common at the time, as parchment was both durable and expensive, so publications regarded as unnecessary or unimportant were frequently used to strengthen other, more precious books.

Aleksander Brückner discovered the sermons on March 25, 1890, at the Imperial Public Library in St. Petersburg, Russian Empire.

He was studying an ancient Latin codex, which had belonged to the Warsaw University library, and was confiscated by the Russians after the November Uprising (1831).

During World War II, the Holy Cross Sermons were taken to Canada for safekeeping.

Written on parchment, they had been cut into thin strips and used to reinforce the binding of a 15th-century Latin manuscript.

They manifest a variety of linguistic archaisms, for instance: 1) Hard-stem declension of the pronoun *tъnъ 'this one': Nom.