Bigthan was a eunuch or chamberlain who kept the door of King Ahasuerus’s court. With Teresh, he conspired against the king’s life, but Mordecai discovered the plot.
The conspiracy of Bigthan and Teresh was recorded in the royal chronicles after Mordecai reported it. The conspirators were later hanged, and the record became important in the events of Esther.
Bigthan served as a palace guard or doorkeeper in the court of Ahasuerus. His position gave him access to the royal household and opportunity to plot against the king.