Thiruvallur name specifies, the sleeping position of Lord Balaji, in the Veeraraghava temple of Thiruvallur. Later people named it as Trivellore.

History
The district Thiruvallur was craved out from Chengapattu district. In the past this region was under a chain of regimes commencing from the Pallavas during the 7th century, ending with Nawab of Arcot during the early part of 19th century and then came under British rule. In the year 1687, the Golconda rulers were defeated and a region came under the Moghul emperors of Delhi. In 1825,it again came under British rule till 1947 of Indian Independence.

Geography
The district is bounded by Kanchipuram district at south, Vellore district in the west, Bay of Bengal in the east and Tamil Nadu in the north. The average annual rainfall of the district is 1104mm. Thiruvallur is located 12 15` to 13 15`N latitude and 79 15` to80 20`E altitude. The district spread over in the area of 3422 sq. km.

Economy

Nearly 47% of the population depends on agriculture in this district. The major corps of this district are rice, cumbu, ragi, green gram, black gram, sugar cane and groundnut. Animal husbandry is the subsidiary occupation of the district due to the presence of a number of small and marginal farmers. Big industrial houses in the key areas are Handlooms. Weaving, Oil Refinery, Fertilizers etc. Thiruvallur is one of the fastest growing districts in Tamil Nadu. The district has many leading industries like Madras Refineries, Madras Fertilizers, Manali Petro Chemicals, MRF, Ashok Leyland, TI Cycles, Britannia India Ltd, Parry India Ltd and Hindustan Motors. There are 16 Industrial Estates established in Thiruvallur.

Government
The District Collector, who is an officer of Indian administrative Division, heads the district. He is responsible for the law and order and maintenance of the district.

Transport
By Road- National Highway no-45 is the closest road near Thiruvellure. Bus service is well connected to Tamil Nadu and with in the city of Thiruvallur.

Division
Thiruvallur district is divided into eight Talukas. They are Thiruvallur, Poonamallee, Ambattur, Ponneri, Gummidipoondi, Uthukottai, Tiruttani, and Pallipattu.

Demographics
As per 2001 Census, Thiruvallur had a population of 2,754,756. The district has average literacy rate of 76.90%, higher than the national average rate.

Culture
Tamil is the average used language in Thiruvallur. The main festivals of the district are TiruttaniAdi-Kiruthikai Peruvizha, Periyapalayam Adi-Peruvizha celebration of 10 days, Thiruvallur Sri Veeraraghava Temple Amavasya celebration, and Mahalaya Amavasya day.

Various temple of the district are -
Ammaiyar Mukhti Adaintha, Karaikal.
Devi Karumariamman Temple, Thiruverkadu.
Lord Arulmigu Subramaniya Swami Temple, Tiruttani.
Lord Shiva Temple and Ashramam, Tamnaraipakkam.
Lord Shiva Temple, Coovam-Kadambathur and Tiruvlangadu.
Lord Veeraraghava Perumal Temple, Thiruvallur
Murugan Temple
Sri Bhavaniamman Temple.
Vadivudaiamman Temple.
Sri Viswaroopa Panchamukha Anjaneyaswami Temple.

Visiting Places of Thiruvallur
Poondi Reservoir- It is a village situated at a distance of 60 km from Chennai. Poondi name is derived from the Tamil version Poondu, the shrub which was once abundant in this place. It has a huge reservoir called Sathyamurthy Sagar. The area of reservoir is about 121/2 sq. miles.