A legend is a genre of folklore that consists of a narrative featuring human actions, believed or perceived to have taken place in human history. Narratives in this genre may demonstrate human values, and possess certain qualities that give the tale verisimilitude. Legend, for its active and passive participants, may include miracles. Legends may be transformed over time to keep them fresh and vital. Many legends operate within the realm of uncertainty, never being entirely believed by the participants, but also never being resolutely doubted. Legends are sometimes distinguished from myths in that they concern human beings as the main characters rather than gods, and sometimes in that they have some sort of historical basis whereas myths generally do not. The Brothers Grimm defined legend as "folktale historically grounded". A by-product of the "concern with human beings" is the long list of legendary creatures, leaving no "resolute doubt" that legends are "historically grounded." A modern folklorist's professional definition of legend was proposed by Timothy R. Tangherlini in 1990: Legend, typically, is a short (mono-) episodic, traditional, highly ecotypified historicized narrative performed in a conversational mode, reflecting on a psychological level a symbolic representation of folk belief and collective experiences and serving as a reaffirmation of commonly held values of the group to whose tradition it belongs. Legend is a loanword from Old French that entered English usage circa 1340. The Old French noun legende derives from the Medieval Latin legenda. In its early English-language usage, the word indicated a narrative of an event. The word legendary was originally a noun (introduced in the 1510s) meaning a collection or corpus of legends. This word changed to legendry, and legendary became the adjectival form. By 1613, English-speaking Protestants began to use the word when they wished to imply that an event (especially the story of any saint not acknowledged in John Foxe's Actes and Monuments) was fictitious.