What was the Language used in Scottish highlands 10th century?

The language used in the Scottish Highlands in the 10th century was Old Gaelic. This is the ancestor of modern Scottish Gaelic.

Here's why:

* The Picts: While the exact language of the Picts (who inhabited the Highlands before the arrival of the Gaels) is unknown, it is generally believed they spoke a language related to Brittonic, the family of languages that includes Welsh, Breton, and Cornish. However, the Picts were increasingly absorbed into Gaelic culture, and their language likely gave way to Old Gaelic.

* The Gaels: The Gaelic-speaking people began migrating to Scotland from Ireland around the 5th century AD. By the 10th century, Gaelic had become the dominant language in the Highlands.

* Old Norse Influence: Starting in the 8th century, Vikings (speaking Old Norse) began raiding and settling in parts of the Highlands, particularly the Northern Isles. This resulted in some influence on vocabulary and grammar, but Old Gaelic remained the dominant language.

It's important to note that the 10th century was a time of transition, and the exact language spoken in different parts of the Highlands might have varied. But Old Gaelic was the dominant language throughout the region.