What is the breed of horse that came from a ship migrated island it was originally but now pony?

The horse breed you're likely thinking of is the Exmoor Pony.

Here's why:

* Island Origin: Exmoor ponies originated on the Exmoor National Park in southwest England, a region that was once an island during the last glacial period.

* Ship Migration: While not specifically migrated by ship, Exmoor ponies were likely brought to the Exmoor region by prehistoric people who were already utilizing horses.

* Pony Status: Due to the isolation of the Exmoor region, the ponies evolved into a smaller, hardier breed with strong survival instincts. Their size and characteristics qualify them as ponies.

Let me know if you have any other horse breeds you'd like to know about!