Bonacci Iernus was a early political theorist and philosopher of the Saint Montaigne. He is often styled Duke Iernus posthumously, though he never held a duchy in his lifetime.
Little is known about Bonacci's personal life. The majority of his writings are lost or contested, and of his remaining canonical works, few are widely read. However, in his most famous work, Pandectae Authentica, he describes the foundational principles of Experimentalism (Political Philosophy), which provided the model upon which the Experimental Duchies would be built. His fame is rightly grounded in having invented this philosophy, which most of the Duchies used as the foundation of their political system for hundreds of years.
In addition to his few attested works (most notably the Pandectae), he is often credited with authorship or partial authorship of other classic works. While these claims are most often of dubious provenance, it is generally agreed that he authored one or more of the Letters of the Alphabet of Donisso Donissi. Generally Letters 34 and 38 are granted to be his work, as they reflect themes and theses expressed in works in his canon, though arguments have been made for him having penned up to seven (Letters 31, 33-35, 38-39, and 41).