Peter Jan Beckx (also Pieter Jan Beckx, in French Pierre Jean Beckx, (8 February 1795, Zichem, present day Belgium – 4 March 1887, Rome, Italy) was a Belgian Jesuit, elected 22nd Superior-General of the Society of Jesus, and was active in the latter role.
In 1870, with the reunification of the Italian state, the secular government expressed an intent of nationalising religious properties and the objects therein, he was responsible for saving for the order many books and manuscripts, partly by claiming them as private collections. This was to include the document was later known as the Voynich Manuscript, which retains his ex libris.
His biography on Wikipedia is here, and some information here. The Wikimedia page is here.