According to the Bhagavata Purana, Aditya, the sun god, went around Mount Sumeru sending his rays to the Loka-Aloka range, illuminating half the earth while the other half remained dark.

Once, Priyavrata, the son-in-law of Vishwakarma decided to illuminate the dark regions so that there would be perpetual daylight. Getting onto his chariot, he began to follow the sun-god. After seven rounds, Brahma stopped him and said,

“Stop, Priyavrata. This isn’t your assigned duty in the universe.”

Since Priyavrata has already gone around Sumeru, there were grooves formed on the ground by his chariot wheels. These grooves formed the seven oceans which then gave rise to the seven dvipas or islands.

• Jambu
• Plaksha
• Salmali
• Kusa
• Krauncha
• Saka
• Pushkara

Each one was twice as large as the preceding one. Most of them were named after a sacred tree of the same name, that was said to grow there.