| Name | Type | Circle | Bench | Formed | Notes |
| Inner Austria | Duchy | | | 1379: Partitioned from Austria | 1406: Annexed to Austria |
| Irsee | Abbacy | Swab | | | 1793: Council of Princes |
Isenburg HRE Prince of Isenburg | 1442: County of Budingen and Isenburg | | | | c1100: Division into Isenburg-Limburg and Isenburg-Kempenich 1137: Partitioned into Isenburg-Isenburg and Isenburg-Limburg-Covern 1673: Division into Isenburg, Birstein, Isenburg-Marienborn, Isenburg-Meerholz, Isenburg-Wachtersbach 1806: Joined Confederation of the Rhine |
| Isenburg-Birstein | 1511: County of Birstein 1744: HRE Principality Sovereign Principality | Upp Rhen | | 1628: Partitioned from Isenburg-Büdingen-Birstein | 1635-1643: Occupied by Hesse-Darmstadt 1806: Acquired the mediatized Isenburg-Budingen, Isenburg-Meerholz, Isenburg-Philippseich and Isenburg-Wachtersbach 1806: Joined the Confederation of the Rhine 1810: French occupation 1813: Austrian administration 1816: Annexed by Hesse-Darmstadt |
Isenburg-Büdingen Isenburg-Budingen | 1442: HRE County | | | 1341: Partitioned from Isenburg-Cleeberg 1628: Partitioned from Isenburg-Budingen-Birstein | 1131: ist mention of Gerlach I as Lord of Budingen 1219: 1st mention of Budingen castle 1240: Line died out; territory jointly inherited by Lords of Breuberg and Isenburg 1323: Breuberg lords died out; Isenburg inherited Budingen territory 1511: Partitioned into Isenburg-Budingen-Birstein and Isenburg-Ronneburg (extinct 1601)<1673>Partitioned into Isenburg-Budingen, Isenburg-Meerholz and Isenburg-Wachtersbach 1806: Mediatized to Isenburg 1816: To Hesse-Darmstadt Area: 3.5 sq. mi.; Pop. (1600s): 10,000 |
| Isenburg-Büdingen-Birstein | County | | | 1511: Partitioned from Isenburg-Büdingen | 1628: Partitioned into Isenburg-Büdingen (reduced) and Isenburg-Birstein |
| Isenburg-Cleberg | County | | | 1286: Partitioned from Isenburg-Grenzau | 1341: Partitioned into Isenburg-Büdingen and Isenburg-Grenzau |
| Isenburg-Grenzau | County | | | 1158: Partitioned from Isenburg-Limburg-Covern | 1664: Annexed to Arenberg |
| Isenburg-Limburg-Covern | County | | | 1137: Partitioned from the Niederlahngau | 1158: Partitioned |
| Isenburg-Marienborn | 1673: County | | | | 1725: Incorporated into Isenburg-Meerholz |
| Isenburg-Meerholz | 1673: County | | | 1673: Partitioned from Isenburg-Büdingen | 1806: Incorporated into Isenburg-Birstein |
| Isenburg-Offenbach | County | | | 1628: Partitioned from Isenburg-Büdingen-Birstein | 1758: Partitioned |
| Isenburg-Philippseich | County | | | 1711: Partitioned from Isenburg-Offenbach | |
| Isenburg-Wächtersbach | 1673: County | | | 1673: Partitioned from Isenburg-Büdingen | 1806: Incorporated into Isenburg-Birstein |
| Isny im Allgäu | Imperial City | Swab | SW | c1250 | 1803: Mediatized to the Count of Quadt 1806: annexed to Württemberg |
| Istria | Margaviate | | | 1000s | 1374: Portion passed to Habsburgs 1420: Rest of Istria annexed by Venice 1797: Venetian part to Habsburg Austria 1809-1813: French occupation |
| Itter | Lordship | | | | |