Samut Sakhon was formerly called Tha Chin (Chinese Pier) probably because, in the old days, it had been a trading port for a vast number of Chinese junks. In 1548, a town named Sakhon Buri was established at the mouth of the Tha Chin River. It was a center for recruiting troops from various seaside towns. The name of the town was changed to Mahachai when Klong (canal) Mahachai was dug in 1704 to connect the Tha Chin River to the town. Later, the town was renamed Samut Sakhon by King Rama IV but it is still popularly called Mahachai by its residents.