After the last linked post, I decided to to put this one on, it is a venerable and useable copy which would be a great place to start your Law book collection!
179g Lancelotti, Giovanni Paolo. 1511-1591 Corpus juris canonici emendatum et notis illustratum, Gregorii XIII. Pont. Max. jussu editum ;
indicibus variis, novisq; et appendice Pauli Lancellotti Perusini adauctum … : accesserunt novissimè loci communes uberrimi, summâ diligentiâ ex ipsis canonibus collecti, & ordine ac methodo singulari ad usum fori utriusque fideliter digesti … : Itemq[ue] Liber VII. Decretalium hac primùm editione novis aliquot constitutionibus auctus.
Coloniæ Munatianæ : [s.n.],1661 $sold
Quarto, 5 X 9 inches.  p., 1272 col.,  p., 754 col.,  p., 406 col.,  p., 158 col.,  p., 236 col.,  p. This copy is bound in full vellum, there is slight damp staining and deterioration in the bottom inch or two of the the book for the first quarter of the text, the paper is soft and stained but present and legable.
Lancelotti owes his worldwide reputation to his “Institutiones Juris Canonici”, the text of which is reproduced in most editions of the “Corpus Juris Canonici”. Following the example of the Byzantine Emperor Justinian, who had entrusted to three professors the task of drawing up an elementary work on Roman law entitled the “Institutiones”, intended for use in the schools, Lancelotti conceived the plan of a like work on the Catholic Church’s canon law. Pope Paul IV charged him officially with the execution of his plan, and for this purpose he went to Rome in 1557. To his great regret, neither Paul IV who died in 1559, nor his successor Pius IV gave authentic and official approbation to his work, published by Lancelotti at Perugia in 1563 as an entirely private venture.
The “Institutiones” are divided into four books, treating successively persons, things (especially marriage), judgments and crimes. This division was inspired by a principle of Roman law: Omne jus quo utimur vel ad personas attinet, vel ad res, vel ad actiones (All our law treats of persons, or things, or judicial procedure.) It is a small and very simple didactic work, and may be considered a clear, convenient resume of canon law. Its divisions have been followed on broad lines by later authors of elementary treatises on canon law, and they have also borrowed its title “Institutiones”. Lancelotti, however, erred when he applied to canon law the unsuitable divisions of Roman law.
Having been published before the promulgation of the Council of Trent, this work had not the advantage of following its decrees; subsequent editors have remedied this defect by notes and commentaries. The best-known editions are those of Doujat (Paris, 1684; Venice, 1739), and Christian Thomasius (Halle, 1715–17).
Lancelotti’s other writings are: “Institutionum juris canonici commentarium” (Perugia, 1560; Lyons, 1579), in which he gives the history of his aforesaid work; “De comparatione juris pontificii et caesarei et utriusque interpretandi ratione” (Lyons, 1574); “Regularum ex universo pontificio jure libri tres” (Perugia, 1587); “Quaestio an in cautione de non offendendo praestita comprehendantur banniti nostri temporis” (Lyons, 1587).
Since the second half of the 13th century, Corpus juris canonici in contradistinction to Corpus juris civilis, or Roman law, generally denoted the following collections: the “Decretals” of Gregory IX; those of Boniface VIII (Sixth Book of the Decretals); those of Clement V (Clementinæ) i. e. the collections which at that time, with the Decretum of Gratian, were taught and explained at the universities. At the present day, under the above title are commonly understood these three collections with the addition of the Decretum of Gratian, the Extravagantes (laws ‘circulating outside’ the standard sources) of John XXII, and the Extravagantes Communes.
Thus understood, the term dates back to the 16th century and was officially sanctioned by Gregory XIII (Cum pro munere, 1 July 1580). The earliest editions of these texts printed under the now usual title of Corpus juris canonici, date from the end of the 16th century (Frankfort, 8vo, 1586; Paris, fol., 1587).