Otto, also spelled Othon (1 June 1815 – 26 July 1867), is a royal prince of Bavaria who became the first modern King of Greece in 1832 under the Convention of London.

He reigns until his deposition in 1862.

The second son of the philhellene King Ludwig I of Bavaria, Otto ascends the newly created throne of Greece while still a minor.

His government is initially run by a three-man regency council made up of Bavarian court officials.

Upon reaching his majority, Otto removes the regents when they prove unpopular with the people and he rules as an absolute monarch.

Eventually his subjects' demands for a Constitution prove overwhelming and in the face of an armed but peaceful insurrection, Otto grants a Constitution in 1843.

Throughout his reign, Otto faces political challenges concerning Greece's financial weakness and the role of the government in the affairs of the Church.

The politics of Greece of this era was based on affiliations with the three Great Powers, and Otto's ability to maintain the support of the powers is key to his remaining in power.

To remain strong, Otto has to play the interests of each of the Great Powers' Greek adherents against the others, while not aggravating the Great Powers.

When Greece is blockaded by the (British) Royal Navy in 1850 and again in 1853, to stop Greece from attacking the Ottoman Empire during the Crimean War, Otto's standing among Greeks suffers.

As a result, there is an assassination attempt on the Queen and finally, in 1862, Otto is deposed while in the countryside.

He dies in exile in Bavaria in 1867.

In Greek writings unfriendly to King Otto, the time of his reign is sometimes called "Bavarokratia" ("Rule of the Bavarians"), a term comparable to "Frankokratia" ("Rule of the Franks, i.e.

the Latin Empire established by West European "Franks" who conquered the Byzantine lands in 1204) and to "Turkokratia" ("Rule of the Turks", i.e.

the centuries of Ottoman rule.

This term implied that the King was another foreign ruler whom Greeks had to overthrow.