1152:

Frederick I elected Holy Roman Emperor

Also known as "Barbarossa" (red-beard), Frederick was frequently at odds with the papacy over issues of authority and was even excommunicated by Pope Alexander III. He was able to consolidate power in Germany but lost territory in northern Italy. Frederick drowned while crossing the Saleph River during the Third Crusade.

1351:

Ramathibodi becomes King of Siam

Ramathibodi set up his capital in Ayutthaya, which as an international port helped increase the prosperity and power of the nation. He also laid the foundations of the Siamese legal system, which was not significantly changed until the 19th century.

1461:

Edward IV takes the English throne

In the long and convoluted English Wars of the Roses, Edward and his supporters (including Warwick the Kingmaker), after a victory at Mortimer's Cross, reached London before the rival Lancastrians and was proclaimed king. He then sealed his ascent to the throne with a victory at Towton from which his primary opponent, Henry VI's queen Margaret of Anjou, fled.

1394:

Henry the Navigator

Prince Henry is known primarily for his insatiable interest in exploration and navigation. As a patron of naval sciences, he was responsible for the development of the Portuguese caravel and increased naval commerce as well as advances in cartographic techniques and navigational instruments.

1193:

Saladin