Pseudoisidore AB

The AB version of the False Decretals was called thus by Hinschius because he assumed it was a derivative, mixed version drawing on both A and B. This was mainly due to his dating of the principal manuscript, Vat. lat. 630, to the eleventh century although in fact it was produced in the ninth century. Both the structure and the text of AB are closer to the Hispana than other versions of Pseudoisidore. Hinschius explained this by later reworking, but modern scholarship prefers the much simpler explanation that AB is the earliest of the major recensions, and that B and C in particular are derivative of AB (Fuhrmann p. 156). Like A1, AB (and also B and C) contain all three parts of the False Decretals (first decretal part, conciliar part, second decretal part) but are slightly shorter in part three.

Manuscripts

Eric Knibbs, who has studied the manuscript tradition of Pseudoisidore with great erudition, has declared that Vat. lat. 630 (his V630) is "our best copy of the A/B recension of the False Decretals". As for other manuscripts, he was very cautious (https://web.archive.org/web/20220526231244/https://pseudo-isidore.com/vat-lat-630/):

At the same time, the extent of the influence of V630 within the A/B recension is far less clear. The only certain derivative is Saint-Omer, Bibliothèque municipale, Ms. 189 (s. XI), which is such an exacting copy of V630 there can be no doubt that it is a codex descriptus. Beyond this manuscript, I know of six further codices that have received A/B classifications:

Bernkastel-Cues, St. Nikolaus Hospital (Cusanus Stiftung), Ms. 52 (s. XII)

Leipzig, Universitätsbibliothek, Ms. II.7 (s. IX: fragmentary):: Leipzig, Universitätsbibliothek, Ms. II.8 (s. XI: fragmentary)

Paris, Bibliothèque nationale de France, Ms. lat. 9629 (s. IX: only Part I is A/B)

Prague, Národní Museum, Ms. XII.D.2 (s. XIV)

Vienna, Österreichishce Nationalbibliothek, Ms. 2133 (s. XII: abbreviated)

Editions and Literature

See the main article Pseudoisidore, False Decretals