Genesis 25:1-2, 4
Genesis 25:1-2 NIV
Abraham had taken another wife, whose name was Keturah. She bore him Zimran, Jokshan, Medan, Midian, Ishbak and Shuah.
Genesis 25:4 NIV
The sons of Midian were Ephah, Epher, Hanok, Abida and Eldaah. All these were descendants of Keturah.