The Chaldeans are an ancient Semitic people who lived in the region of Mesopotamia, particularly in southern Babylonia. They are known for their contributions to early civilization, including advancements in astronomy, mathematics, and writing. The Chaldeans played a significant role in the development of the Babylonian Empire and are often associated with the famous king Nebuchadnezzar II. Today, the term "Chaldean" also refers to a modern ethnic group of Iraqi Christians who trace their heritage back to these ancient people. Many Chaldeans have migrated to various countries, including the United States, where they maintain their cultural and religious traditions, primarily within the Chaldean Catholic Church.