List of states in the Holy Roman Empire (O)

This is a list of states in the Holy Roman Empire beginning with the letter O:

Name	Type	Imperial circle	Imperial diet	History
Oberbronn	Lordship	n/a	n/a	1232: First mentioned; fief of Lichtenberg 1352: Sold to Ochsenstein as fief of Lichtenberg 1382: Sold to Lichtenberg 1452: Sold to Lützelstein as fief of Lichtenberg 1480: To Zweibrücken-Bitsch 1551: To Leiningen-Westerburg-Leiningen 1622: To Leiningen-Westerburg-Oberbronn 1665: 2/3 to Hesse-Homburg, 1/3 to Sinclair 1727: Hessian portion to Hohenlohe-Waldenburg-Bartenstein 1732: Sinclair portion to Lewenhaupt 1764: Part of Hohenlohe portion to de Dietrich 1789: All to France
Oberehnheim (Obernai)	Imperial City	Upp Rhen	RH	1248: Free Imperial City 1679: To France
Oberelsaß See: Upper Alsace	Landgraviate
Obermünster in Regensburg	Abbacy	Bav	RP	1000s: Established with imperial immediacy 1315: HRE Princess of the Empire 1803: To the Archbishopric of Regensburg 1810: To Bavaria; suppressed
Oberried	Provostry	n/a	n/a	1237: Formed 1249: Abolished 1255: Reestablished 1496: Advocacy to Freiburg within Further Austria 1725: Advocacy to St Blaise's Abbey within Further Austria 1806: To Baden
Obersalm See: Salm in the Vosges	County
Oberstein	Lordship	n/a	n/a	1075: First mentioned; to Stein 1250: Line Daun-Oberstein established 1364: Partitioned into Oberstein-Gundheim and Oberstein-Kredenburg
Oberstein-Gundheim	Lordship	n/a	n/a	1364: Partitioned from Oberstein 1683: Extinct; to the Palatinate 1699: To Greiffenclau
Oberstein-Kredenburg	Lordship	n/a	n/a	1364: Partitioned from Oberstein 1602: Extinct; to Speyer
Obwalden	Imperial Valley	n/a	n/a	To Lenzburg 11th Century: Donated to Beromünster Abbey ?: To Murbach Abbey 1291: Sold to Habsburg; with Nidwalden became a founding member of the Swiss League 1324: Imperial immediacy 1648: Left Empire as member of Swiss Confederation
Ochsenhausen	1391: Abbey	Swab	SP	1093: Priory of St. Blaise's Abbey 1391: Independent abbey 1495: Imperial immediacy 1803: To Schaesberg-Retersbeck (Tannheim), Sinzendorf (Winterrieden) and Metternich-Winneburg and Beilstein (remainder) 1806: All to Württemberg
Ochsenstein	Lordship	n/a	n/a	1186: First mentioned; branch of Geroldseck 1391: Quarter of Ochsenstein sold to the Palatinate 1485: Extinct; to Zweibrücken-Bitsch
Odenheim and Bruchsal	Abbey 1503: Provostry	Upp Rhen	RP	1110-8 1161: Imperial immediacy 1496: HRE Lord 1503: Converted to provostry 1507: Relocated to Bruchsal 1803: To Baden
Oettingen (Öttingen)	County	n/a	n/a	1147: First mentioned; related to the House of Hohenstaufen 1363: Acquired Spiegelberg 1418: Partitioned into Oettingen-Oettingen and Oettingen-Wallerstein
Oettingen-Baldern	County	Swab	SC	1623: Partitioned from Oettingen-Wallerstein 1798: Extinct; to Oettingen-Wallerstein
Oettingen-Flochberg	County	Swab	SC	1442: Partitioned from Oettingen-Wallerstein 1522: Partitioned into itself and Oettingen-Wallerstein 1548: Extinct; to Oettingen-Wallerstein
Oettingen-Oettingen	County 1674: Principality	Swab	SC	1418: Partitioned from Oettingen 1440: Extinct; to Oettingen-Wallerstein 1442: Partitioned from Oettingen-Wallerstein 1674: HRE Prince 1731: Extinct; to Oettingen-Wallerstein
Oettingen-Spielberg	County 1734: Principality	Swab	SC / PR	1623: Partitioned from Oettingen-Wallerstein 1734: HRE Prince 1803: Bench of Princes 1806: To Bavaria 1810: Parts to Württemberg
Oettingen-Wallerstein	County 1774: Principality	Swab	SC / PR	1418: Partitioned from Oettingen 1442: Partitioned into Oettingen-Oettingen, itself and Oettingen-Flochberg 1486: Extinct; divided between Oettingen-Flochberg and Oettingen-Oettingen 1522: Partitioned from Oettingen-Flochberg 1549: Extinct; to Frederick V of Oettingen-Oettingen by marriage, who assumed the name Oettingen-Wallerstein 1623: Partitioned into Oettingen-Spielberg, itself and Oettingen-Baldern 1774: HRE Prince 1803: Bench of Princes 1806: To Bavaria 1810: Parts to Württemberg
Offenburg	Imperial City	Swab	SW	before 1240: Imperial Free City 1803: To Baden
Olbrück	Lordship	Low Rhen	WE	1190: Purchased by Wied from the Archbishopric of Cologne 1244: Wied extinct; Olbrück was divided and shared ultimately with a dozen families, often in dispute with each other 1555: All to Waldbott von Bassenheim 1788: Along with Pirmont was used to give access to the Westphalian counts 1794: To France 1815: To Prussia
Oldenburg Grand Duke of Oldenburg, Heir in Norway, Duke of Schleswig, Holstein, Stormarn, Ditmarshes & Oldenburg, Prince of Lübeck and Birkenfeld, Lord of Jever and Kniphausen	County 1777: Duchy 1815: Grand Duchy	Low Rhen	PR	1108: First mentioned; fief of Saxony 1143: Partitioned into Wildeshausen and itself 1181: Imperial immediacy c. 1278: Partitioned into itself and Oldenburg-Delmenhorst 1463: Partitioned into itself and Oldenburg-Delmenhorst 1577: Partitioned into itself and Oldenburg-Delmenhorst 1667: Extinct; to Denmark 1773: To Paul of Russia; then to Frederick Augustus of Lübeck 1777: HRE Duke 1810: To France 1814: Restored 1815: Grand Duke
Oldenburg-Delmenhorst	County	Low Rhen	PR	c. 1278: Partitioned from Oldenburg 1447: Extinct; to Oldenburg 1463: Partitioned from Oldenburg 1482: To Oldenburg 1483: To the Bishopric of Münster 1484: Extinct 1547: To Oldenburg 1577: Partitioned from Oldenburg 1647: Extinct; to Oldenburg
Orange	County 1173: Principality	none	none	11th century: Independence from Provence 1121: Extinct in male line; to Aumelas by marriage 1173: Extinct; to Baux by marriage; HRE Prince 1193: To Baux-Orange 1289: Acquired Baux 1417: Extinct; to Chalon-Arlay 1544: To William of Nassau-Dillenburg, who took the name Orange-Nassau 1702: To France, who enfeoffed Francis Louis of Conti 1713: To France, attached to the Dauphiné
Orange-Nassau	Principality	none	none	1544: Created when William of Nassau-Dillenburg inherited Orange 1702: Extinct; succession dispute between Nassau-Dietz who took the name Orange-Nassau, and Prussia. Orange itself seized by France 1739: Acquired Nassau-Hadamar and Nassau-Dillenburg 1743: Acquired Nassau-Siegen 1747: Acquired the Netherlands 1795: Left bank territory to France 1806: United with Nassau-Orange-Fulda; then dispersed between various states 1815: King of the Netherlands and Grand Duke of Luxembourg
Orlamünde	County	n/a	n/a	1032-1040: Mentioned, to counts of Orlamünde By 1060: Extinct; to Weimar 1062: To Weimar-Orlamünde
Orsini and Rosenberg Prince of Orsini and Rosenberg, Baron of Lerchenau and Grafenstein	1681: HRE Count (Personalist) 1790: HRE Prince (Personalist)	n/a	FR	1681: Formed 13th century: First mentioned 1681: Granted personalist vote in the Bench of Franconian Counts 1684: Adopted style of Orsini-Rosenberg
Ortenau (Mortenau)	Landvogtei	n/a	n/a	763: First mentioned; gau county of the Carolingian Empire 1007: To the Bishopric of Bamberg ?: To Zähringen 1218: Seized by the Emperor 1261: To Geroldseck The Ortenau disintegrated soon after, though the title was held variously by Bach, Fürstenberg, Mörsperg, Ochsenstein and Oettingen, amongst others 1803: Much of the Ortenau to Breisgau-Modena and Baden 1819: All to Baden
Ortenburg in Carinthia	County	n/a	n/a	1072: First mentioned; possibly related to Grögling-Hirschberg 1306: Imperial immediacy 1418: Extinct; to Celje 1456: Extinct; to Austria
Ortenburg (Ortenberg) Count of Ortenburg, Count and Lord of Tambach	County	Bav	WT	1135: Partitioned from Carinthia in the former lands of Vohburg-Passau 1145: Acquired advocacies around Passau 1158: Acquired much of Vornbach 1163: Acquired Murach 1173: Acquired Kraiburg and Marquartstein 1188: Acquired Sulzbach; partitioned into Ortenburg-Kraiburg and Ortenburg-Ortenburg 1272: Remaining territories held by Ortenburg-Ortenburg; henceforth known as Ortenburg 1319: Acquired Wildenegg 1381: Side line Ortenburg-Dorfbach founded 1395: Partitioned into Ortenburg-Neuortenburg and Ortenburg-Altortenburg 1446: Reunited by Ortenburg-Neuortenburg 1517: Acquired Mattighofen 1805: To Bavaria; received in exchange Tambach 1806: Tambach to Bavaria
Ortenburg-Altortenburg	County	n/a	n/a	1395: Partitioned from Ortenburg 1416: Acquired Niederaltaich Abbey 1446: Extinct; to Ortenburg-Neuortenburg
Ortenburg-Dorfbach	County	n/a	n/a	1381: Founded upon marriage of Alrams I with Barbara von Rottau; fief of Ortenburg 1431: Imperial immediacy 1461: Extinct; to Ortenburg-Neuortenburg 1652: Sold to Peckenzell
Ortenburg-Kraiburg	County	n/a	n/a	1188: Partitioned from Ortenburg 1200: Acquired Rotter 1208: Acquired County Palatine of Bavaria and Neuburg 1217: Acquired Griesbach-Waxenberg 1239: Lost Ramsau and territories in Brixen to Regensburg 1248: Extinct in male line; lost County Palatine of Bavaria 1256: To Werdenberg-Sargans by marriage 1259: Sold to Lower Bavaria
Ortenburg-Murach	County	n/a	n/a	1238: Partitioned from Ortenburg-Ortenburg 1268: Made fief of Upper Bavaria 1272: Sold to Upper Bavaria 1285: Extinct
Ortenburg-Neuortenburg	County	n/a	n/a	1395: Partitioned from Ortenburg 1445: Acquired Saldenburg 1446: Renamed to Ortenburg
Ortenburg-Ortenburg	County	n/a	n/a	1188: Partitioned from Ortenburg 1217: Acquired Neustadt 1229: Imperial immediacy 1238: Partitioned into itself and Ortenburg-Murach 1257: Extinct; to Gebhard of Ortenburg-Murach 1272: Renamed to Ortenburg
Osnabrück	Bishopric	Low Rhen	EC	783: Fief of Saxony 1180: Fief of Tecklenburg 1226: HRE Prince of the Empire 1236: Imperial immediacy After 1648: Osnabrück alternately ruled by a Protestant Administrator and Catholic Prince-Bishop 1803: To Hanover 1806: To Prussia 1807: To Westphalia 1810: To France 1815: To Hanover
Osterberg	Lordship 1712: Barony	n/a	n/a	1225: First mentioned; to Elchingen Abbey by 1448: Sold to Ochsenhausen Abbey 1455: Sold to Rechberg-Hohenrechberg 1460: To Rechberg-Kronburg 1577: To Rechberg-Osterberg 1679: Sold to Meyer von Röfingen auf Bühl who assumed the name Osterberg 1712: HRE Barony 1806: To Bavaria
Öttingen See: Oettingen
Ottobeuren	Abbacy	Swab	SP	764: Formed 1299: Imperial immediacy 1624: Fief of the Bishopric of Augsburg 1710: Imperial immediacy 1802: To Bavaria
Overijssel	Lordship	Burg	n/a	11th Century: Territory nominally ceded to the Bishopric of Utrecht as the Oversticht 1336: To Guelders 1347: To the Bishopric of Utrecht 1528: To the Spanish Netherlands; Burgundian Circle 1580: To the Netherlands 1795: To the Batavian Republic 1810: To France 1815: To the Netherlands