Excerpts from Books and Wikipedia
" . . . he is generally considered to be the founder and first king of the medieval German state, known until then as East Francia. . . . Henry built an extensive system of fortifications and mobile heavy cavalry across Germany to neutralize the Magyar threat and in 933 routed them at the Battle of Riade, ending Magyar attacks for the next 21 years and giving rise to a sense of German nationhood. Henry greatly expanded German hegemony in Europe with his defeat of the Slavs in 929 at the Battle of Lenzen along the Elbe river, by compelling the submission of Duke Wenceslaus I of Bohemia through an invasion of the Duchy of Bohemia the same year and by conquering Danish realms in Schleswig in 934. . . . Henry planned an expedition to Rome to be crowned as Holy Roman Emperor by the Pope, but the design was thwarted by a hunting accident near the royal palace of Bodfeld in the autumn of 935 that mortally injured him." [Wikipedia]