Serabit el-Khadem is also the site of Hathor's Temple, dated to the 12th Dynasty. Petrie excavated at the site in the first decade of the 20th century, and there he found evidence of the first earliest alphabetic inscriptions called proto-Sinaitic script, recording the names of Semitic workers and labor.
Sources
Petrie, William Flinders. 1906. Researches in Sinai. Entire document available on the web for free.
Phillips, Wendell 1948 Recent discoveries in the Egyptian Faiyum and Sinai. Science 107:666-670.
This glossary entry is part of the Dictionary of Archaeology. Any mistakes are the responsibility of Kris Hirst.

