Question: What was the language Auctor comes from during the era of the king who united the tribes in the 9th century later known as?

Knowledge 1: Germans
The migration-period peoples who later coalesced into a "German" ethnicity were the Germanic tribes of the Saxons, Franci, Thuringii, Alamanni and Bavarii. These five tribes, sometimes with inclusion of the Frisians, are considered as the major groups to take part in the formation of the Germans. The varieties of the German language are still divided up into these groups. Linguists distinguish low Saxon, Franconian, Bavarian, Thuringian and Alemannic varieties in modern German. By the 9th century, the large tribes which lived on the territory of modern Germany had been united under the rule of the Frankish king Charlemagne, known in German as Karl der Große. Much of what is now Eastern Germany became Slavonic-speaking (Sorbs and Veleti), after these areas were vacated by Germanic tribes (Vandals, Lombards, Burgundians and Suebi amongst others) which had migrated into the former areas of the Roman Empire. [SEP] Knowledge 2: Middle Ages
Charlemagne's court in Aachen was the centre of the cultural revival sometimes referred to as the "Carolingian Renaissance". Literacy increased, as did development in the arts, architecture and jurisprudence, as well as liturgical and scriptural studies. The English monk Alcuin (d. 804) was invited to Aachen and brought the education available in the monasteries of Northumbria. Charlemagne's chancery—or writing office—made use of a new script today known as Carolingian minuscule,[M] allowing a common writing style that advanced communication across much of Europe. Charlemagne sponsored changes in church liturgy, imposing the Roman form of church service on his domains, as well as the Gregorian chant in liturgical music for the churches. An important activity for scholars during this period was the copying, correcting, and dissemination of basic works on religious and secular topics, with the aim of encouraging learning. New works on religious topics and schoolbooks were also produced. Grammarians of the period modified the Latin language, changing it from the Classical Latin of the Roman Empire into a more flexible form to fit the needs of the church and government. By the reign of Charlemagne, the language had so diverged from the classical that it was later called Medieval Latin. [SEP] Knowledge 3: Auctor
Auctor is Latin for author or originator. The term is used in Scholasticism for a "renowned scholar", and in biological taxonomy for the scientist describing a species or other taxon. The term is widely replaced by author in English-language works.
Knowledge 1: Old English
Each of these four dialects was associated with an independent kingdom on the island. Of these, Northumbria south of the Tyne, and most of Mercia, were overrun by the Vikings during the 9th century. The portion of Mercia that was successfully defended, and all of Kent, were then integrated into Wessex under Alfred the Great. From that time on, the West Saxon dialect (then in the form now known as Early West Saxon) became standardised as the language of government, and as the basis for the many works of literature and religious materials produced or translated from Latin in that period. [SEP] Knowledge 2: Old English
With the unification of the Anglo-Saxon kingdoms (outside the Danelaw) by Alfred the Great in the later 9th century, the language of government and literature became standardised around the West Saxon dialect (Early West Saxon). Alfred advocated education in English alongside Latin, and had many works translated into the English language; some of them, such as Pope Gregory I's treatise Pastoral Care, appear to have been translated by Alfred himself. In Old English, typical of the development of literature, poetry arose before prose, but King Alfred the Great (871 to 901) chiefly inspired the growth of prose. [SEP] Knowledge 3: Auctor
Auctor is Latin for author or originator. The term is used in Scholasticism for a "renowned scholar", and in biological taxonomy for the scientist describing a species or other taxon. The term is widely replaced by author in English-language works.
Knowledge 1: Auctor
Auctor is Latin for author or originator. The term is used in Scholasticism for a "renowned scholar", and in biological taxonomy for the scientist describing a species or other taxon. The term is widely replaced by author in English-language works. [SEP] Knowledge 2: Old English
With the unification of the Anglo-Saxon kingdoms (outside the Danelaw) by Alfred the Great in the later 9th century, the language of government and literature became standardised around the West Saxon dialect (Early West Saxon). Alfred advocated education in English alongside Latin, and had many works translated into the English language; some of them, such as Pope Gregory I's treatise Pastoral Care, appear to have been translated by Alfred himself. In Old English, typical of the development of literature, poetry arose before prose, but King Alfred the Great (871 to 901) chiefly inspired the growth of prose. [SEP] Knowledge 3: Middle Ages
Charlemagne's court in Aachen was the centre of the cultural revival sometimes referred to as the "Carolingian Renaissance". Literacy increased, as did development in the arts, architecture and jurisprudence, as well as liturgical and scriptural studies. The English monk Alcuin (d. 804) was invited to Aachen and brought the education available in the monasteries of Northumbria. Charlemagne's chancery—or writing office—made use of a new script today known as Carolingian minuscule,[M] allowing a common writing style that advanced communication across much of Europe. Charlemagne sponsored changes in church liturgy, imposing the Roman form of church service on his domains, as well as the Gregorian chant in liturgical music for the churches. An important activity for scholars during this period was the copying, correcting, and dissemination of basic works on religious and secular topics, with the aim of encouraging learning. New works on religious topics and schoolbooks were also produced. Grammarians of the period modified the Latin language, changing it from the Classical Latin of the Roman Empire into a more flexible form to fit the needs of the church and government. By the reign of Charlemagne, the language had so diverged from the classical that it was later called Medieval Latin.

Answer: Medieval Latin