Archeological digs suggest a settlement existed on the northern bank of the Merbok River by the 1st millennium CE. The Merbok settlement, Sungai Batu was built near the river's estuary. The early history of Kedah, can be traced from various sources, from the prehistoric period, most famously the archaeological site of Bujang Valley, the early maritime trade of India, Persia, and the Arabs to the written works of early Chinese pilgrims and early Chinese records, and later to the partly-historical Hikayat Merong Mahawangsa and the Al-Tarikh Salasilah Negeri Kedah.