| Clue | Source | Date |
|---|---|---|
| 1401, in Roman numerals | Eugene Sheffer | 15 Apr 2025 |
| Start of the 15th century | Newsday | 21 Jul 2023 |
| 1401, in Roman numerals | Eugene Sheffer | 07 May 2021 |
| Early 15th-century year | ||
| Early 15th-century year | ||
| 15th century date | ||
| 15th-century start | ||
| 15th century date | ||
| Year in Boniface IX's reign | ||
| 15th-century date | ||
| Year in Boniface IX's reign | ||
| 15th-century date | ||
| Caesar's 1,401 | ||
| Start of the 15th century | ||
| Start of the 15th century | ||
| CDLXVII tripled | ||
| Start of the 15th century | ||
| 15th-century date |