The ethnonymic meaning of leičiai, e.g. "Lithuanians", is known from several sources. This word is used by Latvians to name Lithuanians: leiši, sg. leitis. In Samogitian dialect there were words "leičiuoti" (to speak in other than Samogitian, or to speak in Aukštaitian dialect) and "leičiukas, leičiūkas" (person speaking in another dialect than Samogitian, has an accent). Compare, for example, with modern Lithuanian "žemaičiuoti" (to speak in the Samogitian dialect). In historical written sources, an important example is known from one participant of the Conference of Lutsk in 1429. John Steinkeller, who was a member of a council of Wrocław (Breslau), wrote in a letter addressed to his home town, that Sigismund, Holy Roman Emperor, was going to grant Vytautas the title of the King of Lithuanians: "her wolde machen herczog Wytolten eynen konyng der Leytten." The word forms, which have meanings Lithuanian, Lithuanians, Lithuania and are most likely derived from the word "leitis", are constantly found in the historical sources from the 14th and 15th centuries. For example, Lithuania is rendered as in writing as "czwicshen Lythen und Prewssen" (1415); as "das land Litten" with a further clarification that it was Aukštaitija in a narrative of a participant or witness of the Battle of Strėva. The ruler of Lithuanians was rendered as "die Litischen konige" in the chronicle of Wigand von Marburg. It seems that the presence of such forms with -ei- in Latvian (more known in a western part), German and Samogitian dialect itself has a high possibility that the forms could derive from Western Balts, but it is unclear why they have no suffix -uva / -ava.