Principality of Reuss-Greiz

The Principality of Reuss-Greiz (Fürstentum Reuß-Greiz), officially called the Principality of the Reuss Elder Line (Fürstentum Reuß älterer Linie) after 1848, was a sovereign state in the German Empire, ruled by members of the House of Reuss. The Counts Reuss of Greiz, Lower-Greiz and Upper-Greiz (Reuß zu Greiz, Untergreiz und Obergreiz) were elevated to princely status in 1778 and thereafter bore the title of Prince Reuss, Elder Line, or Prince Reuss of Greiz.

Similarly to the more numerous Reuss Junior Line, the male members of this house were all named "Heinrich", in honour of Emperor Heinrich VI, who had benefited the family. They were numbered sequentially by birth, rather than by reign, with the last series beginning with Heinrich I (born 1693) and ending with Heinrich XXIV (1878–1927).

The territory had an area of 317 km2 and over 72,000 inhabitants in 1910.

Reuss-Greiz preserved the Frankfurt Parliament flag, which later became the flag of Germany.

Territory
In 1919, in the aftermath of World War I, the territory of the Elder Line was merged with that of the Junior Line as the People's State of Reuss, which was incorporated into the new state of Thuringia in 1920. The Elder Line died out in 1927 with the death of the childless Heinrich XXIV, after which its claims were passed to the Junior Line.

Notable figures

 * Princess Hermine Reuss of Greiz, second wife of former German Emperor Wilhelm II
 * Princess Caroline Reuss of Greiz, wife of Wilhelm Ernst, Grand Duke of Saxe-Weimar-Eisenach
 * Prince Heinrich XV of Reuss-Plauen, Generalfeldmarschall of the Holy Roman Empire