How did demotic script develop from hieratic and hieroglyphic writing?

The demotic script emerged as a highly cursive evolution of the earlier hieroglyphic writing system and the hieratic script. While hieroglyphs were primarily used for formal inscriptions, hieratic served as a faster, more convenient cursive method for administrative and literary purposes throughout the pharaonic period.123

During the reign of Psamtik I (664–610 BCE), demotic began to replace hieratic for secular, everyday documents—a transition reflected in its Egyptian name, sekh shat, or "writing for documents". By the 5th century BCE, demotic had become the standard for business and literary use across Egypt, while hieratic was increasingly relegated to religious texts.123

The development of these scripts was driven by the need for efficiency; as scribes wrote rapidly with ink on papyrus, the original pictorial forms of hieroglyphs were simplified into the cursive strokes of hieratic and, eventually, the even more abbreviated forms of demotic. Despite these changes, the underlying phonetic principles of the original hieroglyphic system remained foundational to the development of these later scripts.234