Historically, Old Saxon and Old Dutch were considered to be distinct dialects of an otherwise unitary language rather than two languages, primarily because they were linked through a dialect continuum spanning the modern Netherlands and Germany. However, while these two languages both shared the same historical origins and some very similar writing styles, Old Saxon shows a slightly reduced morphology compared to Old Dutch, which retained some grammatical distinctions that Old Saxon abandoned. There are also various differences in their phonological evolution, Old Saxon being classified as an Ingvaeonic language, whereas Old Dutch is one of the Istvaeonic languages.