A sermon of 1275 AD by Berthold von Regensburg made the earliest known distinction between the speech of the Niderlender and that of the Oberlender. The Niderlender, or speakers of Low German, were anyone living in the lowlands from the Baltic Sea to the Netherlands, while the Oberlender, who spoke High German, lived in more elevated terrain. The first known such distinction was made in Dutch Ц a Low German variant Ц in a printed book of 1482, which mentioned nederlantsche and oberlantsche sprake, still with the same ranges, with the meaning of neder duutsche and hoghen duutsche. Martin Luther, however, a generation later, used Niderlender to mean the population of the Burgundian Netherlands, a small state consisting of several lowland counties ruled by the Duke of Burgundy since its creation by Charles the Bald of the Holy Roman Empire in 843. By that time also northern Germany was using dudesch for their variant as opposed to duutsch in the low countries. The southerners referred to their speech as diutesch. In the 16th century while Martin Luther was working out a compromise High German for his translation of the Bible, societies called rederijkerskamers, "chambers of rhetoric," were being formed in Flanders and Holland between 1550 and 1650, which at first attempted to impose a Latin structure on Dutch, on the presumption that Latin grammar had a "universal character." However in 1559 Jan van den Werve published his grammar Den schat der Duytsscher Talen in Dutch and so did Dirck Volckertszoon Coornhert (Eenen nieuwen ABC of Materi-boeck) in 1564. The Latinizing tenden y changed course with the joint publication in 1584 by De Eglantier, the rhetoric society of Amsterdam, of the first comprehensive Dutch grammar, Twe-spraack vande Nederduitsche letterkunst/ ofte Vant spellen ende eyghenscap des Nederduitschen taals. Hendrick Laurenszoon Spieghel was a major contributor but others contributed as well. Within the Indo-European language tree, Dutch is grouped within the Germanic languages, which means it shares a common ancestor with languages such as English, German, and Scandinavian languages. This common, but not direct, ancestor (proto-language) of all contemporary Germanic languages is called Proto-Germanic, commonly assumed to have originated in approximately the mid-1st millennium BC in Iron Age northern Europe. All Germanic languages are united by subjection to the sound shifts of Grimm's law and Verner's law which originated Proto-Germanic. These two laws define the basic differentiating features of Germanic languages that separate them from other Indo-European languages. There are no known documents in Proto-Germanic, which was unwritten, and virtually all our knowledge of this early language has been obtained by application of the comparative method. All modern Germanic languages (such as English, German, Dutch, etc.) gradually split off from Proto-Germanic, beginning around the Early Middle Ages. As the earliest surviving Germanic writing, there are a few inscriptions in a runic script from Scandinavia dated to c. 200. It obviously represents Proto-Norse spoken in Scandinavia after it had split as a local dialect from common Proto-Germanic.