Periplus of the Erythraean Sea

The Periplus of the Erythraean Sea is a Sea guide for sailors in the Indian Ocean written during the 1st century CE.
The document describes two sea routes from Egypt, one across to India and the other down to Africa, with all distances measured from Berenice.

The Periplus was written in the first century CE, by an unknown author who appears to have been from Alexandria, Egypt.
The name is derived from the Greek ‘Erythra Thalassa’, meaning Red Sea. Red is the colour which is produced by a type of bacteria in the Arabian Sea and associated Gulfs, which is visible to the eye, and can stretch in ‘blooms’ for hundreds of miles.
The name ‘Erythraean Sea’ was used to describe the northwest Indian Ocean, and included the Red Sea, the Gulf of Aden, and the Persian Gulf. Today, it is known as the Arabian Sea.
Written in Greek, the Periplus consists of 66 chapters, describing how to navigate and trade between Ports in the Red Sea, the Gulf of Aden, the Indian Ocean, India and East Africa known as Azania.
All distances to foreign ports are taken with Berenice as the starting point.

A tenth century edition from Byzantium is held in the Heidelberg University Library.
A fifteenth century inaccurate copy of the tenth century edition is held in the British Museum.

‘On the Erythraean Sea’
- 5 books by Agatharchides, four books are lost, the fifth book has survived intact, describing the lands around the Red Sea and the Horn of Africa.
Affairs in Asia
- 10 books by Agatharchides, lost.
Affairs in Europe
- 49 books by Agatharchides, lost.

‘Natural History Book VI’
- In this work Pliny the Elder (23-79 CE) directly quotes Agatharchides.
- Agatharchides was also directly quoted by Strabo and Diodorus Siculus.

The author names a first century CE Greek Navigator called ‘Hippalus’ as the discoverer of the Southwest Monsoon wind, also known as the ‘Hippalus’ in Roman spelling, and thus the direct route to India, without following the Arabian and Indian coastlines.
However, the Ancient Greeks already knew the Southwest Monsoon, which they spelt as ‘Hypalus’.
Strabo in his ‘Geography’, credits ‘Eudoxus of Cyzicus’, commissioned by Ptolemy VIII of Egypt, of first discovering the Southwest Monsoon. He travelled direct to India twice, first in 118 BCE using an Indian pilot, then again in 116 BCE unaided. Hippalus may have been his navigator.

Chapters 1-18 describe the Route from Berenice down to the East Coast of Africa, known as Azania.
The Periplus describes Rhapta as the last port of Azania, being two days south of the Menouthias Islands, which was most probably the Zanzibar Archipelago.
- Berenice (The Start)
  - Egypt
- Adulis, and Avalites
  - Ethiopia
- Opone
  - Somalia, known as the centre of the Cinnamon trade.
- Malao
  - Somalia.
- Rhapta (The Terminus)
  - The capital of Azania, the area including the coasts of Tanzania, Kenya and Somalia.
  - Azania is mentioned by the Periplus as being subject to the Sabaean Kingdom, an Ally of Rome.
  - Sailing time was c. 90-140 days from Berenice.