The beautiful Latin MS 198 of the John Rylands Library preserves one of two currently known manuscript copies of the Servite Lorenzo Opimo of Bologna’s Scriptum on the Sentences, the only such text by a Servite that survives. In 1494, the Chapter General of the Servite Order made Lorenzo the order’s teaching doctor, since the representatives declared that his work, primarily his questions on the Sentences, would be required reading for Servite students and masters of theology. No doubt as a result, Lorenzo’s Scriptum was printed in Venice in 1532. To most medieval intellectual historians, the printing, the author, and even the religious order are virtually unknown. This two-part article puts this unique text in its doctrinal and institutional context. Part I argues that Lorenzo delivered his Sentences lectures at the University of Paris in 1370–71, presents and analyses the tradition of the three textual witnesses, and offers a question list.