| 501 | unknown | Alina Maria de Roumanie | Romania (House of) | — | | unknown | 2 ch.Children (no sourced line of succession) | 38 |
| 502 | unknown | Princess Sophie Bonaparte | Bonaparte (House of) | 🇫🇷FR | | Charles, Prince Napoléon | 0 ch. | 34 |
| 503 | Duke of Württembergc | Wilhelm, Duke of WürttembergDuke of Württemberg (c) | Württemberg (House of) | 🇩🇪DE | | Duke Friedrich, Hereditary Duke of Württemberg | 0 ch. | 32 |
| 504 | unknown | Fallon Rayman | Karađorđević (House of) | 🇬🇧GB | | unknown | 0 ch. | 31 |
| 505 | Prince of Beirac | Afonso, Prince of BeiraPrince of Beira (c) | Braganza (House of) | 🇵🇹PT | | Duarte Pio, Duke of Braganza | 0 ch. | 30 |
| 506 | Duchess of Württembergc | Duchess Pauline of WürttembergDuchess of Württemberg (c) | Württemberg (House of) | 🇬🇧GB | | unknown | 0 ch. | 29 |
| 507 | Duchess of Württembergc | Duchess Sophie-Dorothea of WürttembergDuchess of Württemberg (c) | Württemberg (House of) | — | | Duke Friedrich, Hereditary Duke of Württemberg | 0 ch. | 29 |
| 508 | Duke of Portoc | Infante Dinis, Duke of PortoDuke of Porto (c) | Braganza (House of) | 🇵🇹PT | | Duarte Pio, Duke of Braganza | 0 ch. | 26 |
| 509 | Donc | Juan Urdangarín y de BorbónDon (c) | Bourbon (House of) | 🇪🇸ES | | unknown | 0 ch. | 27 |
| 510 | Prince of Wiedc | Prince Maximilian, 9th Prince of WiedPrince of Wied (c) | Wied-Neuwied (House of) | 🇩🇪DE | | Prince Carl, 8th Prince of Wied | 0 ch. | 27 |
| 511 | Princess of Bourbon-Parmac | Princess Zita of Bourbon-ParmaPrincess of Bourbon-Parma (c) | Bourbon-Parma (House of) | 🇫🇷FR | | unknown | 0 ch. | 27 |
| 512 | Donc | Pablo Urdangarín y de BorbónDon (c) | Bourbon (House of) | 🇪🇸ES | | unknown | 0 ch. | 25 |
| 513 | Prince of Greece and Denmark | Prince Achileas-Andreas of Greece and DenmarkPrince of Greece and Denmark | Glücksburg (House of) | 🇺🇸US+1 | | Pavlos, Crown Prince of Greece | 0 ch. | 26 |
| 514 | Donc | Miguel Urdangarín y de BorbónDon (c) | Bourbon (House of) | 🇪🇸ES | | unknown | 0 ch. | 24 |
| 515 | Doñac | Irene Urdangarin y Borbón, Grandee of SpainDoña (c) | Bourbon (House of) | 🇪🇸ES | | unknown | 0 ch. | 21 |
| 516 | Prince of Anhaltc | Prince Julius of AnhaltPrince of Anhalt (c) | Ascania (House of) | — | | unknown | 0 ch. | 15 |
| 517 | Princess of Bavariac | Princess Alva of BavariaPrincess of Bavaria (c) | Wittelsbach (House of) | — | | Prince Manuel of Bavaria | 0 ch. | 16 |
| 518 | unknown | Kohen de Roumanie-Kreuger | Romania (House of) | 🇺🇸US+1 | | Michael de Roumanie-Kreuger | 0 ch. | 14 |
| 519 | Prince of Prussiac | Prince Heinrich of PrussiaPrince of Prussia (c) | Hohenzollern (House of) | — | | Georg Friedrich Prinz von Preussen | 0 ch. | 9 |
| 520 | Prince of Hanoverc | Prince Welf August of HanoverPrince of Hanover (c) | Hanover (House of) | 🇩🇪DE | | Prince Ernst August of Hanover | 0 ch. | 7 |
| 521 | Princess of Hanoverc | Princess Eleanora of HanoverPrincess of Hanover (c) | Hanover (House of) | 🇩🇪DE | | Prince Ernst August of Hanover | 0 ch. | 5 |
| 522 | unknown | Mihai de Roumanie | Romania (House of) | 🇷🇴RO | | Nicholas Medforth-Mills | 0 ch. | 4 |
| 523 | unknown | Prince Louis Bonaparte | Bonaparte (House of) | 🇫🇷FR | | Jean-Christophe, Prince Napoléon | 0 ch. | 3 |
| 524 | Princess of Serbiac | Princess Marija of SerbiaPrincess of Serbia (c) | Karađorđević (House of) | 🇷🇸RS | | Philip, Hereditary Prince of Yugoslavia | 0 ch. | 3 |
| 525 | unknown | Augustus Mihai de Roumanie-Metcalfe | Romania (House of) | 🇬🇧GB+1 | | Elisabeta Karina de Roumanie | 0 ch. | 2 |
| 526 | unknown | Q141751829 | Karađorđević (House of) | — | | Prince Alexander of Yugoslavia | 0 ch. | 0 |
| 527 | unknown | Marie Eleonore von Bredow | Schwarzenberg (House of) | — | | Karel VI Schwarzenberg | 1 ch.Children (no sourced line of succession) | 90 |
| 528 | unknown | Dagmar Baronin von Fürstenberg | Fürstenberg (House of) | — | | unknown | 2 ch.Children (no sourced line of succession) | ~88 |
| 529 | Prince of Löwenstein-Wertheim-Rosenbergc | Alois Konstantin zu Löwenstein-Wertheim-RosenbergPrince of Löwenstein-Wertheim-Rosenberg (c) | Löwenstein-Wertheim | 🇩🇪DE | | unknown | 4 ch.Children (no sourced line of succession) | 84 |
| 530 | Princessc | Christa von Thurn und TaxisPrincess (c) | Thurn and Taxis (House of) | 🇩🇪DE | | unknown | 2 ch.Children (no sourced line of succession) | 84 |
| 531 | unknown | Laetitia d'Arenberg | Arenberg (House of) | 🇺🇾UY+1 | | unknown | 2 ch.Children (no sourced line of succession) | 85 |
| 532 | unknown | Jaroslav Lobkowicz | Lobkowicz (House of) | 🇨🇿CZ | | Jaroslav Claude of Lobkowicz | 3 ch.Children (no sourced line of succession) | 84 |
| 533 | unknown | Elisabeth Regina Gabriela zu Schwarzenberg | Schwarzenberg (House of) | — | | unknown | 7 ch.Children (no sourced line of succession) | 79 |
| 534 | unknown | Fritz von Thurn und Taxis | Thurn and Taxis (House of) | 🇦🇹AT+1 | | unknown | 0 ch. | 76 |
| 535 | unknown | Prince Sebastian von Fürstenberg | Fürstenberg (House of) | — | | Tassilo Fürstenberg | 1 ch.Children (no sourced line of succession) | ~76 |
| 536 | Duke of Castel Duinoc | Carlo Alessandro, 3rd Duke of Castel DuinoDuke of Castel Duino (c) | Thurn and Taxis (House of) | 🇮🇹IT | | Raimundo, 2nd Duke of Castel Duino | 0 ch. | 74 |
| 537 | unknown | Filip Zdeněk Lobkowicz | Lobkowicz (House of) | 🇨🇿CZ | | Jaroslav Claude of Lobkowicz | 0 ch. | 72 |
| 538 | unknown | Johannes Lobkowicz | Lobkowicz (House of) | 🇨🇿CZ+1 | | unknown | 5 ch.Children (no sourced line of succession) | 72 |
| 539 | Prince of Windisch-Graetzc | Mariano Hugo, Prince of Windisch-GraetzPrince of Windisch-Graetz (c) | Windisch-Graetz | 🇦🇹AT | | unknown | 3 ch.Children (no sourced line of succession) | 71 |
| 540 | unknown | Anton Prinz von Lobkowicz | Lobkowicz (House of) | — | | Otakar Lobkowicz | 0 ch. | 70 |
| 541 | Duke of Arenbergc | Prince Léopold, 13th Duke of ArenbergDuke of Arenberg (c) | Arenberg (House of) | 🇧🇪BE | | unknown | 3 ch.Children (no sourced line of succession) | 70 |
| 542 | unknown | Gloria von Thurn und Taxis | Thurn and Taxis (House of) | 🇩🇪DE | | unknown | 3 ch.Children (no sourced line of succession) | 66 |
| 543 | Duke of Arenbergc | Prince Pierre d'Arenberg, 4th Duke of ArenbergDuke of Arenberg (c) | Arenberg (House of) | — | | unknown | 1 ch.Children (no sourced line of succession) | 65 |
| 544 | unknown | William Lobkowicz | Lobkowicz (House of) | 🇺🇸US | | Martin Maximillian Georg von Lobkowicz | 1 ch.Children (no sourced line of succession) | 65 |
| 545 | unknown | Erich von Waldburg zu Zeil und Trauchburg | Waldburg (House of) | 🇩🇪DE | | Georg von Waldburg-Zeil-Trauchburg | 5 ch.Children (no sourced line of succession) | 63 |
| 546 | unknown | Johannes Nepomucenus Schwarzenberg | Schwarzenberg (House of) | 🇦🇹AT | | Karel Schwarzenberg | 0 ch. | 58 |
| 547 | Prince of Hohenlohe-Langenburgc | Philipp, Prince of Hohenlohe-LangenburgPrince of Hohenlohe-Langenburg (c) | Hohenlohe-Langenburg (House of) | 🇩🇪DE | | Kraft, Prince of Hohenlohe-Langenburg | 3 ch.Children (no sourced line of succession) | 56 |
| 548 | unknown | Prince Alexander von Fürstenberg | Fürstenberg (House of) | 🇺🇸US | | Prince Egon von Fürstenberg | 2 ch.Children (no sourced line of succession) | 56 |
| 549 | unknown | Alexandra von Fürstenberg | Fürstenberg (House of) | 🇺🇸US | | unknown | 2 ch.Children (no sourced line of succession) | 54 |
| 550 | Princess of Hohenlohe-Bartensteinc | Princess Margherita of Hohenlohe-BartensteinPrincess of Hohenlohe-Bartenstein (c) | Hohenlohe (House of) | 🇩🇪DE | | unknown | 0 ch. | 47 |