The 18th century BC consists of the years 1800-1701 BC. (All dates approximate). * 1800 BC. Birth of Isaac. * 1799 BC. Death of Selug. * 1787 BC. Death of Arpachshad * 1765 BC. Death of Terah. * 1763 BC. Death of Sarah. * 1760 BC. Isaac marries Rebekkah. * 1752 BC. Death of Shelah * 1740 BC. Birth of Jacob and Esau. * 1725 BC. Death of Abraham.