The aim of this paper is to investigate the sources of Corpus Linguistics in order to enlighten the current distinction between the “corpus-based” and “corpus-driven” trends, led respectively by Geoffrey Leech and John Sinclair. Although Corpus Linguistics originates from the London School founded by Daniel Jones and John Rupert Firth in the 1950s, and from the British empirical tradition, both trends have diversely interpreted Firth’s pioneering notions: context of situation, restricted languages, meaning by collocation, lexicogrammar, use, corpus and texts. In this paper, we will examine how these notions have been involved in the making of early pre-computerized and computerized corpora of the English language in the 1960s.