1840 state leaders - Events of 1841 - 1842 state leaders - State leaders by year

Africa

• Ashanti Confederacy - Kwaku Dua I Panyin, Asantehene (1834-1867)
• Buganda - Suna II, King of Buganda (1836-1856)
• Bunyoro - Nyabongo II, Omukama of Bunyoro (1835-1848))
• Burundi - Ntare IV Rugamba, King of Burundi (1796-1852)
• Dahomey - Gézo, King of Dahomey (1818-1856)
• Rwanda - Mutara II Rwogera, King of Rwanda (1830-1853)
• Sokoto Caliphate
  • Caliph - Abu Bakr Atiku, Sokoto Caliph (1837-1842)
  • Grand Vizier - Gidago dan Laima, Sokoto Grand Vizier (1817-1842)
• Zulu - Mpande kaSenzangakhona, King of the Zulu (1840-1872)

Asia

• Afghanistan - Shoja Shah, King of Afghanistan (1839-1842)
  • Mohammad Zaman Khan, Mohammadzay regent (in rebellion)
• China (Qing Dynasty) - Daoguang, Emperor of China (1821-1850)
• Japan
  • Monarch - Ninko, Emperor of Japan (1817-1846)
  • Shogun (Tokugawa) - Tokugawa Ieyoshi, Shogun of Japan (1837-1853)
  • Ryūkyū Kingdom - Shō Iku, King of Ryūkyū (1829-1847)
• Korea (Joseon Dynasty) - Heonjong, King of Joseon (1834-1849)

Europe

• Abkhazia - Mikheil, Prince of Abkhazia (1822-1864)
• Belgium
  • Monarch - Léopold I, King of the Belgians (1831-1865)
  • Cabinet Chief -
    1. Joseph Lebeau, Cabinet Chief of Belgium (1840-1841)
    2. Jean Baptiste, Baron Nothomb, Cabinet Chief of Belgium (1841-1845)
• Denmark -
  • Monarch - Christian VIII, King of Denmark (1839-1848)
  • Prime Minister - Otto Joachim, Minister of State of Denmark (1824-1842)
• France -
  • Monarch - Louis Philippe, King of the French (1830-1848)
  • Prime Minister - Nicolas Jean de Dieu Soult, duc de Dalmatie, Prince Minister of France (1840-1847)
• German Confederation
  • Austria - Ferdinand I, Emperor of Austria (1835-1848)
    • Chancellor - Prince Klemens Wenzel von Metternich, Chancellor of Austria (1821-1848)
  • Prussia -
    • Monarch - Friedrich Wilhelm IV, King of Prussia (1840-1861)
    • Chief Minister -
      1. Count Karl Friedrich Heinrich von Wylich, Chief Minister of Prussia (1823-1841)
      2. Ludwig Gustav von Thile, Chief Minister of Prussia (1841-1848)
  • Bavaria - Ludwig I, King of Bavaria (1825-1848)
  • Saxony - Frederick Augustus, King of Saxony (1836-1854)
  • Hanover - Ernest Augustus, King of Hanover (1837-1851)
  • Württemberg - William, King of Württemberg (1816-1864)
• Hungary - Ferdinand V, King of Hungary (1835-1848)
• Netherlands - William II, King of the Netherlands (1840-1849)
• Portugal - Maria II, Queen of Portugal (1826-1828, 1834-1853)
• Russia - Nicholas I, Tsar of Russia (1825-1855)
• Spain - Isabella II, Queen of Spain (1833-1868)
• Sweden - United Kingdoms of Sweden and Norway - Charles XIV John, King of Sweden (1818-1844)
• Two Sicilies - Ferdinand II, King of the Two Sicilies (1830-1859)
• United Kingdom -
  • Monarch - Victoria, Queen of Great Britain and Ireland (1837-1901)
  • Prime Minister -
    1. William Lamb, 2nd Viscount Melbourne, Prime Minister of the United Kingdom (1835-1841)
    2. Sir Robert Peel, Prime Minister of the United Kingdom (1834-1835, 1841-1846)

Middle East and North Africa

• Abu Dhabi -
  • Co-Sheikh - Khalifa bin Shakhbut, Shaikh of Abu Dhabi (1833-1845)
  • Co-Sheikh - Sultan bin Shakhbut, Shaikh of Abu Dhabi (1833-1845)
• Bahrain - Muhammad ibn Khalifah Al Khalifah, Shaikh of Bahrain (1834-1842)
• Egypt - Muhammad Ali Pasha, Governor of Egypt (1805-1848)
• Kuwait - Sheikh Jabir ibn Abdullah Al Sabah, Ruler of Kuwait (1814-1859)
• Morocco - Abderrahmane, Sultan of Morocco (1822-1859)
• Oman - Sa'id II ibn Sultan, Sultan of Oman (1804-1856)
• Ottoman Empire
  • Monarch - Abd-ul-Mejid, Sultan of the Ottoman Empire (1839-1861)
  • Grand Vizier -
    1. Mehmed Hüsrev Pasha, Ottoman Grand Vizier (1839-1841)
    2. Mehmed Emin Rauf Pasha, Ottoman Grand Vizier (1841)
    3. Izzet Mehmed Pasha, Ottoman Grand Vizier (1841-1842)

North America

• Costa Rica - Braulio Carrillo Colina, Head of State of Costa Rica (1838-1842)
• Texas -
  1. Mirabeau B. Lamar President of the Republic of Texas (1838-1841)
  2. Sam Houston President of the Republic of Texas (1841-1844)
• United States -
  1. Martin Van Buren, President of the United States (1837-1841)
  2. William Henry Harrison, President of the United States (1841)
  3. John Tyler, President of the United States (1841-1845)

Oceania

• Hawaii - Kamehameha III, King of Hawaii (1823-1854)
• New Zealand
  • Monarch - Victoria, Queen of Great Britain and Ireland (1837-1901)
  • Lieutenant-Governor - William Hobson, Lieutenant-Governor of New Zealand (1840-1842)
• Samoa - Malietoa Vai'inupo, Malietoa (?-1841)
• Tonga - Aleamotu'a, Tu'i Kanokupolu (1827-1845)

South America

• Brazil - Pedro II, Emperor of Brazil (1831-1889)
• Mexico -
  1. Anastasio Bustamante, President (1839-1841)
  2. Francisco Javier Echeverría, President (1841-1841)
  3. Antonio López de Santa Anna, President (1841-1842)
• Uruguay - Fructuoso Rivera, President of Uruguay (1839-1843)