Gedaliah was appointed governor during the time that the Babylonians had conquered the land of Judah. After Nebuchadnezzar's Babylonian army had destroyed Jerusalem and had deported many of the Jews, the Babylonians named Gedaliah as governor over the population that was remained.
After he had been appointed as governor, Gedaliah tried to convince some of the Jewish army commanders to remain in Judah and to serve the king of Babylon, assuring them that if they did so, all would be well. But a few months later, Gedaliah was assassinated in the town of Mizpah, by Ishmael, son of Nethaniah. (This is not the same Ishmael who was the brother of Isaac). This Ishmael, the son of Nethaniah, was of royal lineage. He and his men killed Gedaliah and the Chaldeans (Babylonians) who were with Gedaliah.
After the assassination, Gedaliah's followers fled to Egypt because they were afraid that the Babylonians would blame them for killing Gedaliah. They took the prophet Jeremiah with them, despite Jeremiah's pleas that they remain in Judah. Jeremiah was a friend of Gedaliah.
The name Gedaliah means "Great is the Lord."