An early form of Galician-Portuguese was already spoken in the Kingdom of the Suebi and by the year 800 Galician-Portuguese had already become the vernacular of northwestern Iberia. The first known phonetic changes in Vulgar Latin, which began the evolution to Galician-Portuguese, took place during the rule of the Germanic groups, the Suebi (411–585) and Visigoths (585–711). The Galician-Portuguese "inflected infinitive" (or "personal infinitive") and the nasal vowels may have evolved under the influence of local Celtic, (as in Old French). The nasal vowels would thus be a phonologic characteristic of the Vulgar Latin spoken in Roman Gallaecia, but they are not attested in writing until after the 6th and 7th centuries.