This castle complex was located at an altitude of 740 meters above sea level, about 300 meters above the Vorarlberg Rhine Valley on the vertically rising rock ridge above the market, the so-called Schlossberg.
In the last expansion stage at the beginning of the 17th century, the complex extended from the rocky head "Miß" in the north of the castle over the wide castle saddle (castle meadow) and the high castle to the outer works on the "Gsätzle" and "Güggenstein" in the southwestern rocky slope.
The name Alt-Ems (or Alt-Embs) is derived from "Alta-Embs" (Latin "altus" = high) and means something like "High Ems". The name of the town of Hohenems is derived from this today.
The castle, originally a Welf castle and from 1179/1191 a Hohenems castle, was owned by the Ems ministerials and from the end of the 12th century the Alt-Ems castle was one of the most powerful and largest castle complexes in the entire southern German region. The Hohenems fortress served as a place of detention for prominent prisoners such as William III (Sicily) from 1195 or Archbishop Bruno of Cologne in 1206. In 1407 the castle complex was destroyed in the Appenzell War.
Under Count Jakob Hannibal I of Hohenems (1530–1587) extensive renovations and extensions were carried out around 1500 and under Count Kaspar of Hohenems (1573–1640) from 1566 onwards it was expanded into an extensive Renaissance fortress according to plans by Martino Longhi. After the Counts of Hohenems died out, the castle went to Austria in 1765 and was auctioned off for demolition in 1792.
In the years from 1938 to 1940 and 1965/66, the castle ruins were extensively restored, and from 2006 to 2007 the ruins were renovated again.[1] Today, the ruins are mainly privately owned by the Waldburg-Zeil-Hohenems family.
Source: Wikipedia