Royllo – Phantom Island West of the Canaries, 1424 Chart
Isla de Royllo · Royllo phantom
Portolan phantom (1424–1448)·Venetian–Portuguese cartography·🇪🇸 Atlantic Ocean, Canaries phantom, Spain
About
About Royllo – Phantom Island West of the Canaries, 1424 Chart
Royllo, a 30 km phantom west of Ferro (El Hierro) on the 1424 Pizzigano chart at 29°N 18°W, appears alongside Satanazes and Antillia as part of the Azores–Canaries phantom inflation. The island is drawn isolated, named 'Royllo' (possibly 'Royal' homage). It vanishes after mid-15th c. when Canarian latitude was fixed by Portuguese circumnavigation. No 29°N 18°W seamount exists – the Canary Basin is 3000 m deep. Royllo exemplifies Canaries longitudinal duplication error where Ferro meridian was mis-copied.
Why it mattersExample of Canaries longitude phantom; Royllo anchors Ferro meridian error analysis.
Open questions
Mysteries & theories
Mysteries
- 01Whether Royllo name reflects 'Roy' homage to Portuguese royalty
Theories
- 01Ferro meridian duplication copied Ferro twice, creating Royllo ghost
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- 1424 CE (Pizzigano)
- Period
- Portolan phantom (1424–1448)
- Culture
- Venetian–Portuguese cartography
- Purpose
- Chart phantom – longitudinal duplication
- Abandoned
- 1448 CE (deleted after Ferro discovery)
- Rediscovered
- 1925 Cortesão
- Excavation
- Not applicable
1424
Pizzigano draws Royllo 30 km W of Ferro
1448
Benincasa deletes Royllo
On the ground
Structures & features
29.0000° N · 18.0000° W · 0 m · 3 mapped features
Royllo Islet
island30 km phantom islet at 29°N 18°W at Royllo – Phantom Island West of the Canaries, 1424 Chart
29.0000° N · 18.0000° WFerro Meridian Ghost
canalFerro meridian duplication line – 10 km ghost error at Royllo – Phantom Island West of the Canaries, 1424 Chart
29.0000° N · 18.1000° WCanary Basin Floor
harbour3000 m basin floor proving no land at Royllo – Phantom Island West of the Canaries, 1424 Chart
29.0000° N · 18.0000° W