The article talks about three visits paid in 1609, 1611 and 1612 by prince Janusz Radziwiłł and Daniel Naborowski – one of the most eminent poets of the Polish Baroque – at the court of king James I in London. These visits were related to the wedding plans – Władysław IV Vasa, son of king Sigismund III Vasa, was supposed to marry English princess Elizabeth Stuart. In her honour Naborowski wrote a famous poem entitled "Na oczy królewny angielskiej" ("For English Princess’ Eyes"). During the second visit at the English court, 1st November 1611, Radziwiłł and Naborowski were probably watching the staging of Shakespeare’s "The Tempest" in the Banqueting House in the Palace of Whitehall. The author of the article points out a possible source of Shakespeare’s play which was a text written by a Polish humanist Marcin Kromer, widely known in Europe of those times thanks to its latin translation. Kromer’s text described a story of young prince Sigismund (the future king Sigismund III Vasa) who was born on an island in MalDrm Lake where Eric XIV of Sweden imprisoned his parents: Eric’s brother John III of Sweden and his wife Catherine Jagiellon. A Polish poet Daniel Naborowski might have seen and possibly met William Shakespeare.