The Elder Futhark consists of 24 runes divided into three groups of eight, known as an ætt (singular of ættir), which are said to be ruled over by both a god and goddess. The first ætt is ruled over by Frey and Freyja, the deities of fertility. The second ætt is ruled over by Heimdall and Mordgud, and the third and final ætt is ruled over by Tîwaz and Zisa.