Historical clue formulations

• "Dread river of oath," per Homer — 2026-06-10
• River of Hades — 2025-07-07
• River in which Achilles was dipped — 2024-11-06
• River to Hades — 2024-09-02
• River where Achilles took a dip — 2024-06-05
• Eldest daughter of Oceanus and mother of Nike — 2024-02-16
• Underworld boundary — 2023-06-07
• Mythical river of the underworld — 2022-11-21
• River of Hades — 2022-10-05
• River with a mythical ferryman — 2022-09-21
• "Mr. Roboto" band, 1983 — 2022-08-31
• Infernal river — 2022-08-25
• River on which Greek deities swore their oaths — 2022-07-07
• Mythological river around the underworld — 2021-11-08
• Where Achilles took a dip? — 2020-10-15
• Daughter of Tethys in Greek mythology — 2020-08-08
• Charon's domain — 2020-06-28
• Charon's river — 2020-03-15
• Locale of Charon's ferry — 2019-12-11
• River of Hades — 2019-11-06
• River of the underworld — 2019-05-06
• Home to a mythical ferry — 2019-04-25
• River whose name comes entirely from the last eight letters of the alphabet — 2019-01-10
• River of the underworld — 2018-10-29
• River in which Achilles was dipped — 2018-10-17
• It goes to hell — 2018-08-04
• Band with the top 10 hits "Lady" and "Babe" — 2018-07-19
• Boundary between the earth and the underworld, in myth — 2018-04-22
• River to Hades — 2018-03-27
• Moon of Pluto discovered in 2012 — 2017-07-14
• Something crossed in "The Divine Comedy" — 2016-11-18
• One hell of a river? — 2016-08-23
• River crossed by Orpheus — 2016-08-03
• River to Hades — 2016-06-06
• Underworld river — 2016-05-03
• River with a "dreadful shore," in Shakespeare — 2015-07-26
• River to Hades — 2015-07-14
• River ferried by Charon — 2014-11-05
• River to 16-Across — 2014-09-09
• Zeus swore oaths upon it — 2013-12-08
• Mother of Nike, in Greek myth — 2013-11-28
• Moon of 6-Down named for a mythological river — 2013-11-19
• River of the underworld, in myth — 2013-09-16
• River of Hades — 2013-07-16
• Where Achilles was dipped to make him invincible — 2013-06-28
• River of Hades — 2012-04-09
• Underworld route — 2011-10-23
• River of Hades — 2011-10-17
• "Mr. Roboto" band, 1983 — 2011-10-09
• River ferried by Charon — 2011-09-07