When the Salian dynasty ended with Henry V's death in 1125, the princes chose not to elect the next of kin, but rather Lothair, the moderately powerful but already old Duke of Saxony. When he died in 1137, the princes again aimed to check royal power; accordingly they did not elect Lothair's favoured heir, his son-in-law Henry the Proud of the Welf family, but Conrad III of the Hohenstaufen family, the grandson of Emperor Henry IV and thus a nephew of Emperor Henry V. This led to over a century of strife between the two houses. Conrad ousted the Welfs from their possessions, but after his death in 1152, his nephew Frederick I "Barbarossa" succeeded him and made peace with the Welfs, restoring his cousin Henry the Lion to his – albeit diminished – possessions.

Several Qing officials in Taiwan resolved to resist the cession of Taiwan to Japan under the Treaty of Shimonoseki, and on 23 May declared the island to be an independent Republic of Formosa.

In 1904 the Wrights built the Flyer II. They decided to avoid the expense of travel and bringing supplies to the Outer Banks and set up an airfield at Huffman Prairie, a cow pasture eight miles (13 km) northeast of Dayton. They received permission to use the field rent-free from owner and bank president Torrance Huffman. They invited reporters to their first flight attempt of the year on May 23, on the condition that no photographs be taken.

The British 1939 White paper stipulated that Jewish immigration to Palestine was to be limited to 15,000 a year for the first five years, and would subsequently be contingent on Arab consent.

In recognition of his efforts de Gaulle was promoted to the rank of temporary (acting, in Anglophone parlance) brigadier-general on 23 May 1940.