Sigismund was Holy Roman Emperor for 4 years from 1433 until 1437, and the last Emperor of the House of Luxemburg. He was also one of the longest-ruling Kings of Hungary and Croatia, reigning for 50 years from 1387 to 1437.
Sigismund was born on 14th February 1368, to the son of Holy Roman Emperor Charles IV and Elizabeth of Pomerania in Nuremberg. He was named after Saint Sigismund of Burgundy, the favourite saint of Sigismund's father.
In 1396 he led the Crusade of Nicopolis, which attempted to liberate Bulgaria and save the Byzantine Empire and Constantinople from Ottoman rule. But he was decisively defeated by the Ottoman Empire. Afterwards, he founded the Order of the Dragon to fight the Turks and secured the thrones of Croatia, Germany and Bohemia.
Depicted here is a gold coin issued during his reign from Buda mint. The obverse of a coin depicts St. Ladislaus, crowned, nimbate, and mantled standing facing, axe in the right hand, globus cruciger in left. On the other hand, the reverse of a coin engraved quadripartite shield with stripes and Bohemian lions.
Image Source: https://en.wikipedia.org