Complex sentence: Tarasicodissa, as he was known as a young man, was an Isaurian, a people who lived on the south-western Mediterranean coast of Anatolia, in what is now the coastal Antalya Province along the south-west corner of modern day Turkey.
Split into simpler sentences: Tarasicodissa, as he was known as a young man, was an Isaurian. The Isaurians were a people who lived on the south-western Mediterranean coast of Anatolia, in what is now the coastal Antalya Province along the south-west corner of modern day Turkey.