Irish clans were traditional social groups in Ireland, often based on shared ancestry and territory. Each clan was typically led by a chieftain and consisted of extended families who worked together for mutual support and protection. Clans played a significant role in Irish society, influencing local governance and culture. The most famous Irish clans include the O'Neills, O'Briens, and MacCarthys. Clans often had their own unique symbols, such as family crests, and were associated with specific regions. Over time, many clans faced challenges from external forces, leading to changes in their structure and influence.