Otto, also spelled Otho (Greek: O Όθων, Βασιλεύς της Ελλάδος, O Óthon, Vasiléfs tis Elládos), was a Bavarian prince who became the first modern King of Greece in 1832 under the Convention of London. He reigned until he was deposed in 1862.
The second son of King Ludwig I of Bavaria, Otto ascended the newly created throne of Greece while still a minor. His government was initially run by a three-man regency council made up of Bavarian court officials. Upon reaching his majority, Otto removed the regents when they proved unpopular with the people and he ruled as an absolute monarch. Eventually his subjects' demands for a Constitution proved overwhelming, and in the face of an armed but peaceful insurrection Otto in 1843 granted a constitution. However he rigged elections using fraud and terror.
Throughout his reign Otto was unable to resolve Greece's poverty and prevent economic meddling from outside. Greek politics in this era was based on affiliations with the three Great Powers, and Otto's ability to maintain the support of the powers was key to his remaining in power. To remain strong, Otto had to play the interests of each of the Great Powers' Greek adherents against the others, while not aggravating the Great Powers. When Greece was blockaded by the British Royal Navy in 1850 and again in 1854, to stop Greece from attacking the Ottoman Empire during the Crimean War, Otto's standing amongst Greeks suffered. As a result, there was an assassination attempt on the Queen, and finally in 1862 Otto was deposed while in the countryside. He died in exile in Bavaria in 1867.
Otto was styled "Βασιλεύς τῆς Ἑλλάδος" (King of Greece). Later kings were styled "Βασιλεύς τῶν Ἑλλήνων" (King of the Hellenes).