De origine actibusque Getarum (lit. The Origin and Deeds of the Getae but referring to the Goths, whom Jordanes considered Getae), or the Getica, written by Jordanes (or Jornandes) in 551, is a summary of a voluminous account by Cassiodorus of the origin and history of the Gothic people, the now lost Libri XII De Rebus Gestis Gothorum. It is significant as the only remaining contemporaneous resource on the origin and history of the Goths. Another important point of this work is the information about the early history and the customs of Slavs.
Because Cassiodorus' original version has not survived, Jordanes' work is one of the most important sources for the period of the migration of the European tribes, and the Ostrogoths and Visigoths in particular, from the 3rd century CE. Cassiodorus' work claims to have the Gothic "Folk songs" -- carmina prisca (Latin) -- as an important source. Recent scholarship regards this as highly questionable. The main purpose of the original work (Cassiodorus's) was to give the Gothic ruling class a glorious past - to match the past of the senatorial families of Roman Italy.
A controversial passage identifies the ancient people of Venedi mentioned by Tacitus, Pliny the Elder and Ptolemy, with the Slavs of the 6th century. As early as 1844, it has been used by many eastern European scholars for supporting the idea of the existence of a Slavic ethnicity much before the last phase of the Late Roman period. Others have rejected this view, based on the absence of concrete archaeological and historiographical data.
The book is important to some medieval historians because it mentions the campaign in Gaul of one Riothamus, "King of the Brettones," who was possibly a source of inspiration for the early stories of King Arthur.
One of the major questions concerning the historicity of the work is whether the identities mentioned are as ancient as stated or date from a later time. The evidence allows a wide range of views, the most skeptical being that the work is mainly mythological, or if Jordanes did exist and is the author, that he describes peoples of the 6th century only. According to the latter, his main source's credibility is questionable for a number of reasons. First, the originality of his main source, Cassiodorus, is debatable because large part of it consists of culling of ancient Greek and Latin authors for descriptions of peoples who might have been Goths. Not only that but it seems that Jordanes has distorted Cassiodorus's narrative by presenting us a cursory abridgement of the latter, mixed with 6th century ethnic names.
It seems clear that, while acceptance of Jordanes at face value may be too naive, a totally skeptical view is not warranted. For example, Jordanes says that the Goths originated in Scandinavia 1490 BC. Some scholars, like Austrian historian Herwig Wolfram, believe that there might be a kernel of truth in that claim, if we assume that a clan of the Gutae left Scandinavia long before the establishment of the Amali in the leadership of the Goths. This clan might have contributed to the ethnogenesis of the Gutones in east Pomerania (see Wielbark culture). Another example is the name of the king Cniva which David S. Potter thinks is genuine because, since it doesn't appear in the fictionalized genealogy of Gothic kings given by Jordanes, he must had found it in a genuine 3rd century source.
A manuscript of the text was rediscovered in Vienna in 1442 by the Italian humanist Enea Silvio Piccolomini. Its editio princeps was issued in 1515 by Konrad Peutinger, followed by many other editions.
The classic edition is that of 19th-century German classical scholar Theodor Mommsen (in Monumenta Germaniae Historica, auctores antiqui, v. ii.). The best surviving manuscript was the Heidelberg manuscript, written in Heidelberg, Germany, probably in the 8th century, but this was destroyed in a fire at Mommsen's house on July 7, 1880. The next of the manuscripts in historical value are the Vaticanus Palatinus of the 10th century, and the Valenciennes manuscript of the 9th century.
Jordanes' work had been well known prior to Mommsen's 1882 edition. It was cited in Edward Gibbon's classic 6 volumes of The History of the Decline and Fall of the Roman Empire (1776), and had been earlier mentioned by Degoreus Whear (1623) who refers to both Jordanes' De regnorum ac temporum successione and to De rebus Geticis.
In his Preface, Jordanes presents his plan
Theodoric died in 526 and Cassiodorus went on to serve his successors in the same capacity. He had not by any means forgotten the task assigned to him by his former king. In 533 a letter ostensibly written by King Athalaric to the senate in Rome, but ghosted by Cassiodorus, mentions the great work on the Goths, now complete, in which Cassiodorus "restored the Amali with the illustriousness of their race." The work must have been written at Ravenna, seat of the Gothic kings, between 526 at latest and 533.
What Cassiodorus did with the manuscripts after that remains unknown. The fact that Jordanes once obtained them from a steward indicates that the wealthy Cassiodorus was able to hire at least one full-time custodian of them and other manuscripts of his; i.e., a private librarian (a custom not unknown even today).
Jordanes says in the preface to Getica that he obtained them from the librarian for three days in order to read them again (relegi). The times and places of these readings have been the concern of many scholars, as this information possibly bears on how much of Getica is based on Cassiodorus.
There are two main theories, one expressed by the Mierow source below, and one by the O'Donnell source below. Mierow's is earlier and does not include a letter cited by O'Donnell.
Gothic sovereignty came to an end with the reconquest of Italy by Belisarius, military chief of staff for Justinian, ending in 539. Cassiodorus' last ghost writing for the Gothic kings was done for Witiges, who was removed to Constantinople in 540. A number of token kings ruled from there while Belisarius established that the Goths were not going to reinvade and retake Italy (which was however taken again by the Lombards after Justinian's death).
Cassiodorus retired in 540 to his home town of Squillace, where he used his wealth to build a monastery with school and library, Vivarium.
Jordanes does cite some writers well before his time, to whose works he had access but we do not, and other writers whose works are still extant. Mierow gives a summary of these, which is reviewed below, and also states other authors he believed were used by Jordanes but were not cited in Getica (refer to the Mierow source cited below). Mierow's list of cited authors is summarized as follows:
Jordanes refers to himself as agrammaticus before his conversion. This obscure statement is sometimes taken to refer to his Latin. Variability, however, characterizes all Late Latin, and besides, the author was not writing just after his conversion (for the meaning of the latter, see under Jordanes), but a whole career later, after associating with many Latin speakers and having read many Latin books. According to him, he should have been grammaticus by that time. More likely, his style reflects the way Latin was under the Goths.
Some of the variabilities are as follows (Mierow):
Orthography. The spelling of many words differs from the classical, which Jordanes would certainly have known. For example, Grecia replaces Graecia; Eoropam, Europam; Atriatici, Adriatici.
Inflection. Substantives migrate between declensions; verbs between conjugations. Some common changes are fourth to second (lacu to laco), second declension adjective to third (magnanimus to magnanimis), i-stems to non-i-stems (mari to mare in the ablative). Gender may change. Verbs may change voice.
One obvious change in a modern direction is the indeclinability of many formerly declined nouns, such as corpus. Also, the -m accusative ending disappears, leaving the preceding vowel or replacing it with -o (Italian, Romanian), as in Danubio for Danubium.
Syntax. Case variability and loss of agreement in prepositional phrases (inter Danubium Margumque fluminibus), change of participial tense (egressi .. et transeuntes), loss of subjunctive in favor of indicative, loss of distinction between principle and subordinate clauses, confusion of subordinating conjunctions.
Semantics. A different vocabulary appears: germanus for frater, proprius for suus, civitas for urbs, pelagus for mare, etc.

