Lahngau

The Lahngau was a medieval territory comprising the middle and lower Lahn River valley in the current German states of Hesse and (partially) Rhineland-Palatinate. The traditional names of the Gau are ''Loganahe Pagus'' or ''Pagus Logenensis''.

The Lahngau was the East Frankish ancestral homeland of the Conradines. It was divided in ca. 900 into the Upper and Lower Lahngau (translated from the German ''Oberlahngau'' and ''Niederlahngau'' /nowiki>or ''Unterlahngau''/nowiki>, respectively).

Location

The western boundary of the Lahngau was near present-day Montabaur. To the west of the Lahngau, extending to the Rhine River, was the Engersgau with its center in the Neuwied Basin. The northwestern border was marked by the watershed of the Westerwald. Northwest and north of the Lahngau was the Auelgau with its central settlements near the mouth of the Sieg River and probably in the Siegerland. North and northeast of the Lahngau was the Hessengau, the former settlement area of the Chatti. Like the Lahngau, the Hessengau would for a time be dominated by the Conradines. Southeast of the Lahngau was the Wettereibagau (later called the Wetterau). South, at the watershed of the Taunus Mountains, was the boundary with the Königssondergau. In the 1845 travel guide '' Le Rhin,'' Victor Hugo notes: "Then comes Braubach, named in a charter of 933, fief of the Counts Arnstein of Lahngau; an Imperial city under Rodolph in 1270, a domain of the Counts of Katznellenbogen in 1283; accruing to Hesse in 1473; to Darmstadt, in 1632, and in 1802 to Nassau."

The exact demarcation of the boundary between Oberlahngau and Niederlahngau has not survived. According to some historians, the approximate boundary is presumed to have been the watershed between the Solmsbach and the Weil River, east of Weilburg. Christian Spielmann writes in 1894, “Weilburg lay in the Niederlahngau. It extended from about the Nister to the Pfahlgraben and from the Gelbach and Aar westward to the Ulmbach and eastward to Weil. Other historians suggest the border was west of Weilburg. Hellmuth Gensicke suggested the watershed between the Kerkerbach and Elbbach as a possible boundary. The following discussion is based on the interpretation of Gensicke assuming a border west Weilburg.

The Carolingian gaus were divided into districts called ''Zentmarken''. For these districts names such as "''(Unter)gau''" (sub-gau), “''Zente''” (center), or “''Mark''” (march) were used. The original ''Zentmarken'' of the Niederlahngau were probably the Reckenforst around Dietkirchen, the Hadamarer Mark, the Ellarer Mark, and the Zente Winnen - Höhn. In the Oberlahngau were the Haiger Mark and the Herborner Mark. The Erdagau should also be understood as a sub-gau of the Lahngau. The assignment of the Kallenbach Zent (or Kallenbergskopf) north of present-day Löhnberg is unclear and depends on which interpretation of the boundary is adopted. With increasingly denser populations, the ''Zentmarken'' were divided or new ones were established.

The population centers of the Lahngau developed from places established at fords on the Lahn. Some of these places go back, according to archaeological finds, to Frankish camps of the 6th and 7th centuries that secured crossings of the Lahn. The urban centers of the Niederlahngau were the later cities of Diez (first mentioned as "''Theodissa''" in 790) and Limburg (first mentioned as "''Lintpurc''" in 910). The centers that developed in the Oberlahngau were Wetzlar (first mentioned as "''Weftifa''" in 832), Haiger (first mentioned as "''Haigrahe''" in 778), and, depending on the course of the border, Weilburg (first mentioned as "''Wilineburch''" in 906).

Dietkirchen (mentioned in 841 as the "''ecclesia Dietkircha''") emerged as an important ecclesiastical center for the Lahngau. In the Middle Ages, the St. Lubentius at Dietkirchen was the seat of an archdeaconry that included all of the areas on the right bank of the Rhine belonging to the Archbishopric of Trier