Moses de Leon is not a shadowy figure. A substantial body of Hebrew writing survives under his own name, most of it produced in the 1280s and 1290s, and it can be read alongside the Zohar rather than only as background to it. Sefer ha-Rimmon, the Book of the Pomegranate, treats the commandments as a symbolic system reflecting the structure of the divine world. Shekel ha-Kodesh and Or Zarua work over the same material, and a run of shorter treatises and responsa fills out the picture of a working kabbalist writing for an educated Hebrew readership rather than for a coterie.
The evidence for his life is thin but real. He is associated with Guadalajara, where much of the signed output was written, and later with Avila. The record places his death at Arevalo in 1305, on a journey home.
Beyond that the documentary trail runs out, and the colour that fills the gap in later accounts comes from a single much repeated report by Isaac of Acre, who wrote that he had gone looking for the ancient manuscript of the Zohar, and that de Leon's widow told him no such manuscript existed because her husband had written the book himself. Scholars differ on how much weight the story bears, since Isaac's account survives only at second hand in a later compilation and its details do not all hang together. It is not the foundation of the modern case, but it is where the modern question begins.