From the Wikipedia page 
Jakub Hořčický (in Latin Jacobus Sinapius) (1575–25 September 1622), later granted the title "z Tepence" ("of Tepenec"), was a Bohemian pharmacist and personal doctor of Emperor Rudolf II. The latinized name is a translation of his family name, which means "mustard" in Czech ("sinapis" in Latin).
According to his college records, Jakub was born in Bořenovice in Moravia in a lower-class family. He initially worked as kitchen helper at the Jesuit school at Krumlov, but was eventually admitted to the Krumlov Seminary of poor students in 1590. There he worked in the college's pharmacy under the overseeing of Martin Schaffner (1564–1608).
Jakub eventually graduated from the Krumlov Gymnasium (current website , and became a pharmacist himself. By 1598 he started studying Aristotelian philosophy at the Clementinum college in Prague (which was later merged with Charles University), but continued working in chemistry and pharmacy. He grew herbs and set up a laboratory at Smichov, the Clementinum's botanical garden. There he distilled a very popular Aqua Sinapis ("water of mustard", perhaps a reference to his own name) whose sale made him a wealthy man. He lent emperor Rudolf II enormous sums of money and received from him an estate in Mělník.
In 1600 he became the administrator of the Jesuit college in Jindřichův Hradec, and in 1606 he became capitaneus and administrator of the properties of the St. George's Convent in the Prague Castle. In 1607 he was named imperial chemist by Rudolf II. In return for curing the emperor of a grave disease, he was ennobled with the title "de Tepenec", presumably after the historic Tepenec Castle (destroyed in 1391) near Olomouc.
In the religious disputes of the early 17th century, Jakub strongly defended the Catholic side. He became the leader of the township of Mělník but was jailed in 1620, when the Protestants took charge of the town. He was subsequently exchanged by another prisoner (Jessenius) and exiled, but later returned to Mělník and lived there the rest of his life.
He died in 1622, from a horse-fall that he had suffered a year before. Two days before his death he was moved to the Clementinum at the care of the Jesuits, and left them the sum of 50,000 gold coins and his Mělník estate. He is buried in the Church of the Savior in the Clementinum.
In 1609 he published a pro-Catholic pamphlet which saw several reprintings. According to a 1777 source, he had written several manuscripts on chemistry and botany
Book dealer Wilfrid Voynich claimed that Jakub's name and title was barely readable at the bottom of the first page of the Voynich Manuscript, and therefore it is believed that the book was once in his possession. Unfortunately, attempts by Voynich to bring out more hidden writing on that page by chemical treatment only succeeded in erasing Jakub's name, which is now preserved only in photocopies. It was later revealed by ultra-violet light and has been compared with other samples of his signature. The manuscript's attested provenance begins with him, the second person stated to have owned it, since the story that it was owned by Emperor Rudolf II rests on a single piece of unsubstantiated hearsay, related at second hand in a letter to Athanasius Kircher.
See also the comments on the equivalent page of the other Voynich wiki