The term "Dacian" refers to the ancient people who inhabited the region known as Dacia, which corresponds to modern-day Romania and parts of Bulgaria, Moldova, Serbia, and Hungary. The Dacians were known for their rich culture, advanced metallurgy, and strong warrior society. They spoke a language related to the Thracian languages and practiced polytheism, worshipping various gods. The Dacians are most famously known for their conflicts with the Roman Empire, particularly during the reign of Emperor Trajan. The Dacian Wars (101-106 AD) ultimately led to the conquest of Dacia by Rome, resulting in significant cultural and economic changes in the region.