Nonthaburi Province is one of the most densely populated provinces in Thailand after Bangkok itself. It covers only 622 sq km (240 sq mi), ranking it 74th in size among the 76 provinces of Thailand. Its population is 1.1 million, which is the 20th position. However the population density places it in second spot.
Nonthaburi Province was created only in 1946. Its provincial capital, Nonthaburi, has a history stretching back to the mid 16th century, when it began as the village of Talat Khwan. It prospered and grew after a canal was carved to divert the flow of the Chao Phraya, passing through Nonthaburi to provide shorter connection between Ayutthaya and Bangkok. King Narai then built a fortification here in 1665, to protect Ayutthaya against attacks from the south.
Today Nonthaburi Province is divided into 6 districts or amphoe. They are Mueang Nonthaburi (Nonthaburi Town), Bang Kruai, Bang Yai, Bang Bua Thong, Sai Noi and Pak Kret.