Like this will ever be complete. Also includes failed states, puppet states, claimed nations, and micronations, for kicks.

• Aachen (Free Imperial City) _{(Aachen 1306–1801)}
• Abbasid Caliphate _{(Kufa 750–762, Baghdad 762–796, Raqqa 796–809, Baghdad 809–836, Samarra 836–892, Baghdad 892–1258, Cairo 1261–1517)}
• Abhira (Kingdom) _{(Valkha 203–467)}
• Abkhazia (Kingdom) _{(Anacopia 778–786, Kutaisi 786–1008)}
• Abkhazia (Principality) _{(Sokhumi 1463–1570)}
• Abkhazia (Autonomous Republic) _{(Sokhumi 1992–1993, *Tbilisi 1993–2006, Chkhalta 2006–2008, *Tbilisi 2008–)}
• Abkhazia (Republic) _{(Sokhumi 1992–)}
• Achaea (Principality) _{(Andravida 1205-1249, Mystras 1249-1261)}
• Acre (Republic) _{(Porto Acre 1899–1900, 1900, 1903)}
• Adal (Sultanate) _{(Zeila 1415–1420, Dakkar 1420–1520, Harar 1520–1577, Aussa 1577)}
• Lucerne (Canton) _{(Lucerne 1386–1798)}
• Philippines (Republic) _{(Manila 1946–)}
• Samo's Empire _{(Wogastisburg 631–658)}
• Switzerland _{(Bern 1848–)}
• Tibet (Empire) _{(Lhasa 618–842)}
• Tibet (Ganden Phodrang) _{(Lhasa 1642–1959, *Dharamsala 1959–)}
• Wabanaki Confederacy _{(Qonasqamkuk 1606–1862, 1993–)}