This is a list of states in the Holy Roman Empire beginning with the letter O. Some historians mark the beginning of the Empire as 800, with the coronation of Frankish king Charlemagne ("Charles the Great").
Name Type Imperial circle Imperial diet History Oberbronn Lordship n/a n/a 1232: First mentioned; fief of Lichtenberg1352: Sold to Ochsenstein as fief of Lichtenberg1382: Sold to Lichtenberg1456: Sold to Lützelstein as fief of Lichtenberg1480: To Zweibrücken-Bitsch1551: To Leiningen-Westerburg-Leiningen1622: To Leiningen-Westerburg-Oberbronn1665: 2/3 to Hesse-Homburg, 1/3 to Sinclair1727: Hessian portion to Hohenlohe-Waldenburg-Bartenstein1732: Sinclair portion to Lewenhaupt1764: Part of Hohenlohe portion to de Dietrich1789: All to France Oberehnheim (Obernai) Imperial City Upp Rhen RH 1240: Free from monastic control as town1354: Joins Décapole1679: To France OberelsaßSee: Upper Alsace Landgraviate Obermünster in Regensburg Abbacy Bav RP 800s: Established with imperial immediacy1315: HRE Princess of the Empire1802: To the Archbishopric of Regensburg1810: To Bavaria; suppressed Oberried Provostry n/a n/a 1237: Formed1249: Abolished1255: Reestablished1496: Advocacy to Freiburg within Further Austria1725: Advocacy to St Blaise's Abbey within Further Austria1806: To Baden ObersalmSee: Salm in the Vosges County Oberstein Lordship n/a n/a 1075: First mentioned; to Stein1250: Line Daun-Oberstein established1364: Partitioned into Oberstein-Gundheim and Oberstein-Kredenburg Oberstein-Gundheim Lordship n/a n/a 1364: Partitioned from Oberstein1661: Extinct; to the Palatinate1699: To Greiffenclau Oberstein-Kredenburg Lordship n/a n/a 1364: Partitioned from Oberstein1602: to Schmidtburg1611: Extinct; to Speyer Obwalden Imperial Valley n/a n/a 11th Century:To Lenzburg12th Century: Donated to Beromünster Abbey?: To Murbach Abbey1291: Sold to Habsburg; with Nidwalden became a founding member of the Swiss League.1309: Imperial immediacy1648: Left Empire as member of Swiss Confederation Ochsenhausen 1391: Abbey Swab SP 1093: Priory of St. Blaise's Abbey1391: Independent abbey1495: Imperial immediacy1803: To Schaesberg-Retersbeck (Tannheim), Sinzendorf (Winterrieden) and Metternich-Winneburg and Beilstein (remainder)1806: All to Württemberg Ochsenstein Lordship n/a n/a 1187: First mentioned; branch of Geroldseck1391: Quarter of Ochsenstein sold to the Palatinate1485: Extinct; to Zweibrücken-Bitsch Odenheim and Bruchsal Abbey1503: Provostry Upp Rhen RP 1100–18: Established1494: Secularization1507: Relocated to Bruchsal1803: To Baden Oettingen (Öttingen) County n/a n/a 1141: First mentioned1363: Acquired Spiegelberg1410: Partitioned into Oettingen-Oettingen and Oettingen-Wallerstein Oettingen-Baldern County Swab SC 1623: Partitioned from Oettingen-Wallerstein1798: Extinct; to Oettingen-Wallerstein Oettingen-Flochberg County Swab SC 1442: Partitioned from Oettingen-Wallerstein1522: Partitioned into itself and Oettingen-Wallerstein1548: Extinct; to Oettingen-Wallerstein Oettingen-Oettingen County1674: Principality Swab SC 1410: Partitioned from Oettingen1440: Extinct; to Oettingen-Wallerstein1442: Partitioned from Oettingen-Wallerstein1674: HRE Prince1731: Extinct; to Oettingen-Wallerstein Oettingen-Spielberg County1734: Principality Swab SC / PR 1623: Partitioned from Oettingen-Wallerstein1734: HRE Prince1803: Bench of Princes1806: To Bavaria1810: Parts to Württemberg Oettingen-Wallerstein County1774: Principality Swab SC / PR 1410: Partitioned from Oettingen1442: Partitioned into Oettingen-Oettingen, itself and Oettingen-Flochberg1486: Extinct; divided between Oettingen-Flochberg and Oettingen-Oettingen1522: Partitioned from Oettingen-Flochberg1549: Extinct; to Frederick V of Oettingen-Oettingen by marriage, who assumed the name Oettingen-Wallerstein1623: Partitioned into Oettingen-Spielberg, itself and Oettingen-Baldern1774: HRE Prince1803: Bench of Princes1806: To Bavaria1810: Parts to Württemberg Offenburg Imperial City Swab SW 1148: First mentioned1240: Imperial Free City1803: To Baden Olbrück Lordship Low Rhen WE 1190: Comissioned by Wied to the Archbishopric of Cologne1244: Wied extinct; Olbrück was divided and shared ultimately with a dozen families, often in dispute with each other1555: All to Waldbott von Bassenheim1794: To France1815: To Prussia OldenburgGrand Duke of Oldenburg, Heir in Norway, Duke of Schleswig, Holstein, Stormarn, Ditmarshes & Oldenburg, Prince of Lübeck and Birkenfeld, Lord of Jever and Kniphausen County1777: Duchy1815: Grand Duchy Low Rhen PR 1108: First mentioned; fief of Saxony1143: Partitioned into Wildeshausen and itself1180: Imperial immediacy1262: Partitioned into itself and Oldenburg-Delmenhorst1447: Reunited with Oldenburg-Delmenhorst1463: Partitioned into itself and Oldenburg-Delmenhorst1547: Reunited with Oldenburg-Delmenhorst1577: Partitioned into itself and Oldenburg-Delmenhorst1617: Reunited with Oldenburg-Delmenhorst1667: Extinct; to Denmark1773: To Paul of Russia; then to Frederick Augustus of Lübeck1777: HRE Duke1810: To France1815: Restored, Grand Duke Oldenburg-Delmenhorst County Low Rhen PR 1262: Partitioned from Oldenburg1447: Extinct; to Oldenburg1463: Partitioned from Oldenburg1482: To Oldenburg1483: To the Bishopric of Münster1484: Extinct1547: To Oldenburg1577: Partitioned from Oldenburg1617: Extinct; to Oldenburg Orange County1173: Principality none none 11th century: Independence from Provence1121: Extinct in male line; to Aumelas by marriage1173: Extinct; to Baux by marriage; HRE Prince1193: To Baux-Orange1289: Acquired Baux1417: Extinct; to Chalon-Arlay1544: To William of Nassau-Dillenburg, who took the name Orange-Nassau1702: To France, who enfeoffed Francis Louis of Conti1713: To France, attached to the Dauphiné Orange-Nassau Principality none none 1544: Created when William of Nassau-Dillenburg inherited Orange1702: Extinct; succession dispute between Nassau-Dietz who took the name Orange-Nassau, and Prussia. Orange itself seized by France1739: Acquired Nassau-Hadamar and Nassau-Dillenburg1743: Acquired Nassau-Siegen1747: Acquired the Netherlands1795: Left bank territory to France1806: United with Nassau-Orange-Fulda; then dispersed between various states1815: King of the Netherlands and Grand Duke of Luxembourg Orlamünde County n/a n/a 1032-1040: Mentioned, to counts of OrlamündeBy 1060: Extinct; to Weimar1062: To Weimar-Orlamünde Orsini and RosenbergPrince of Orsini and Rosenberg, Baron of Lerchenau and Grafenstein 1681: HRE Count (Personalist)1790: HRE Prince (Personalist) n/a FR 1681: Formed13th century: First mentioned1681: Granted personalist vote in the Bench of Franconian Counts1684: Adopted style of Orsini-Rosenberg Ortenau (Mortenau) Landvogtei n/a n/a 763: First mentioned; gau county of the Carolingian Empire1007: To the Bishopric of Bamberg?: To Zähringen1218: Seized by the Emperor1261: To GeroldseckThe Ortenau disintegrated soon after, though the title was held variously by Bach, Fürstenberg, Mörsperg, Ochsenstein and Oettingen, amongst others1803: Much of the Ortenau to Breisgau-Modena and Baden1819: All to Baden Ortenburg in Carinthia County n/a n/a 1072: First mentioned; possibly related to Grögling-Hirschberg1306: Imperial immediacy1418: Extinct; to Celje1456: 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-Passau1145: Acquired advocacies around Passau1158: Acquired much of Vornbach1163: Acquired Murach1173: Acquired Kraiburg and Marquartstein1188: Acquired Sulzbach; partitioned into Ortenburg-Kraiburg and Ortenburg-Ortenburg1272: Remaining territories held by Ortenburg-Ortenburg; henceforth known as Ortenburg1319: Acquired Wildenegg1381: Side line Ortenburg-Dorfbach founded1395: Partitioned into Ortenburg-Neuortenburg and Ortenburg-Altortenburg1446: Reunited by Ortenburg-Neuortenburg1517: Acquired Mattighofen1805: To Bavaria; received in exchange Tambach1806: Tambach to Bavaria Ortenburg-Altortenburg County n/a n/a 1395: Partitioned from Ortenburg1416: Acquired Niederaltaich Abbey1446: Extinct; to Ortenburg-Neuortenburg Ortenburg-Dorfbach County n/a n/a 1381: Founded upon marriage of Alrams I with Barbara von Rottau; fief of Ortenburg1431: Imperial immediacy1461: Extinct; to Ortenburg-Neuortenburg1652: Sold to Peckenzell Ortenburg-Kraiburg County n/a n/a 1188: Partitioned from Ortenburg1200: Acquired Rotter1208: Acquired County Palatine of Bavaria and Neuburg1217: Acquired Griesbach-Waxenberg1239: Lost Ramsau and territories in Brixen to Regensburg1248: Extinct in male line; lost County Palatine of Bavaria1256: To Werdenberg-Sargans by marriage1259: Sold to Lower Bavaria Ortenburg-Murach County n/a n/a 1238: Partitioned from Ortenburg-Ortenburg1268: Made fief of Upper Bavaria1272: Sold to Upper Bavaria1285: Extinct Ortenburg-Neuortenburg County n/a n/a 1395: Partitioned from Ortenburg1445: Acquired Saldenburg1446: Renamed to Ortenburg Ortenburg-Ortenburg County n/a n/a 1188: Partitioned from Ortenburg1217: Acquired Neustadt1229: Imperial immediacy1238: Partitioned into itself and Ortenburg-Murach1257: Extinct; to Gebhard of Ortenburg-Murach1272: Renamed to Ortenburg Osnabrück Bishopric Low Rhen EC 783: Fief of Saxony1180: Fief of Tecklenburg1226: HRE Prince of the Empire1236: Imperial immediacyAfter 1648: Osnabrück alternately ruled by a Protestant Administrator and Catholic Prince-Bishop1803: To Hanover1806: To Prussia1807: To Westphalia1810: To France1815: To Hanover Osterberg Lordship1712: Barony n/a n/a 1225: First mentioned; to Elchingen Abbeyby 1448: Sold to Ochsenhausen Abbey1455: Sold to Rechberg-Hohenrechberg1460: To Rechberg-Kronburg1577: To Rechberg-Osterberg1679: Sold to Meyer von Röfingen auf Bühl who assumed the name Osterberg1712: HRE Barony1806: To Bavaria ÖttingenSee: Oettingen Ottobeuren Abbacy Swab SP 764: Formed1299: Imperial immediacy1624: Fief of the Bishopric of Augsburg1710: Imperial immediacy1802: To Bavaria Overijssel Lordship Burg n/a 11th Century: Territory nominally ceded to the Bishopric of Utrecht as the Oversticht1336: To Guelders1347: To the Bishopric of Utrecht1528: To the Spanish Netherlands; Burgundian Circle1580: To the Netherlands1795: To the Batavian Republic1810: To France1815: To the Netherlands
References