Complex sentence: The professionalism of the poetic tradition was sustained by a Guild of Poets, or Order of Bards, with its own'rule book' emphasizing the making of poetry as a craft.
Split into simpler sentences: The professionalism of the poetic tradition was sustained by a Guild of poets, or Order of bards, with its own'rule book'. This'rule book' emphasised their professionalism and that the making of poetry as a craft.