The County of Nidda ( was a small county of the Holy Roman Empire centred on the city of Nidda in modern Wetteraukreis, Hesse. It was located on the northern edge of the Wetterau river valley and consisted of a relatively cohesive block of land held in fief from the Abbey of Fulda. The County was created by a decree of the Abbey of Fulda, which consolidated the Abbey's possessions in the northern Wetterau. The name "County of Nidda" had become attached to the area by the second half of the eleventh century, when the position of Vogt over the area was given as a fief to . The marriage of his son, , into the around 1100 expanded the family's possessions. From these territories, the County of Nidda was created. The first reference to a member of the family as "Count of Nidda" dates to 1104, during the reign of Volkold II. In 1155, after supporting Count palatine against the Archbishop Arnold of Selenhofen, the family lost Malsburg and other possessions in northern Hesse, meaning that the County was henceforth concentrated in the northern Wetterau region. An endowment of 1187 gives information on the extent of the County. At that point, it contained at least the area between the settlements of Ranstadt, Einartshausen, Wenings und Gelnhaar. The patchy record makes it unclear what other territories belonged to the County. This document was produced in the reign of . He died childless in 1205/6, so the county was inherited by his nephew, , son of and his wife Mechthild, sister of Berthold II. Smaller sections of the county were probably given away as dowries for two of his sisters: Adelheid of Ziegenhain, who married Ulrich I of Münzenberg, and Mechthild, who married Gerlach II, Count of Isenburg. From 1205/06, the County of Nidda was in the possession of the Counts of Ziegenhain, for whom it had only secondary significance compared to the substantially larger . Nidda was formally separated from Ziegenhain and passed to a junior line during the period 1259-1330, but it returned to the Ziegenhain main line after married Lukardis (Luitgart), daughter of the last Count of Nidda, Engelbert I. After John II died childless in 1450, the County of Nidda, along with the County of Ziegenhain, passed to the Landgraviate of Hesse and ceased to exist as a separate lordship. By this point, it consisted of the