Ooty or Udagamandalam (the Tamil version of the original name) precisely described as "Queen of Hill Stations" by Pandit Jawaharlal Nehru, sprawls over an area of 36 sq km with a number of tall buildings cluttering its hill slopes. It is situated at an altitude of 2,240 meters above the Main sea level.
In ancient times, the Nilgiri Hills (including Ooty, Coonoor, Kotagiri & Gudalur) were part of Chera Empire. later it fell in to the hand of ganga dynasty. and then Hoysala empire under king Vishnuvardhana in the 12th century. They then became part of the Kingdom of Mysore of Tipu Sultan who later surrendered them to the British in the 18th century.
John Sullivan, the British governor of neighbouring Coimbatore province, liked the climate of this forested land, and occupied it by taking land from the native tribes (Toda, Irumba and Badaga); often buying up many square kilometres in a day for the price of a few meals.

The hills were developed rapidly under the British Raj because they were almost entirely owned by private British citizens, unlike the rest of India. Ooty served as the summer capital of the Madras Presidency, and had winding hill roads and a complicated rack railway system built by influential and enterprising British citizens with venture capital from the Madras government.

John Sullivan, Collector of Coimbatore district in 1819, first brought this beautiful botanical Garden a heaven to the public eye. But prior to this in 1812, the first Englishmen who were sent up the Nilgris by the Collector of Coimbatore were Mr. Keys, Assistant Revenue Surveyor, and his Assistant, McMahon. They made their way via Dananayakan Kottai to Aracad and the existing village of Denad, and penetrated as far as Kallatti, the lower level of North Ooty, but never set their eyes on the beautiful valley in which Ooty lay. After Keys' visit there was no further expedition until 1818 when J.C.Whish and N.W.Kindersly (Asst. and second Asst. to the Collector of Coimbatore respectively) went up by the Dananayakan Kottai-Denad route, crossed the plateau in a southwestern direction and descended by the Sundapatti pass from Manjakombai to the Bhavani valley and then went back to Coimbatore. The purpose of their visit is not known.

In March 1819, John Sullivan obtained Rs 1,100 (Rupees of those days not to be compared with the present-day rupee) from the Board of Revenue for laying a bridle path up the hill from Sirumugai to Kotagiri and its neighboring village, Dhimatti. The work was executed by McPherson in a period of 2 years starting 1821. This was the only route to the Nilgris from Coimbatore until 1832, when the first Coonoor ghat road was laid, thanks to the then Governor, S.R. Lushington, who got the work executed by Lehardy and Capt. Murray. The present metalled ghat road from Kallar to Coonoor, a distance of 25 km which has 14 hair-pin bends and a gradient of one 18 ft, which facilitated carriage traffic from Madras to Ooty, was mainly constructed by Colonel G.V. Law in 1871. It is gratifying to note that the cascade of the Coonoor river near Wenlock bridge on the Coonoor-Mettupalayam road named after Law, continues to bear the same name.

The Coonoor-Mettupalayam road was extended to Udagamandalam, covering a distance of about 15 km. The Kotagiri-Mettupalayam road (about 34 km long), which was 8 ft wide, to begin with, was widened to 17 ft in 1872-75 with a gradient of one in 17 by the Dist. Engineer, Major Morant R.E. and handed over to the District Board in 1881. During the period from 1819 to 1830, John Sullivan's contribution was, apart from laying the route to Ooty, that he built the first house called Stone House in this place. This formed the nucleus of Government offices. Further, at his own expense, he conducted experiments on agricultural and horticultural crops and in animal husbandry to find the most suitable crops and breeds of milky animals for future settlers next to the magnificent task of laying the road to Ooty, the British took up, around 1880, the amazing task of connecting Mettupalayam to Ooty by rail. A Swiss engineer, M. Riggenback and Major Morant of Kotagiri road fame prepared an estimate of 1,32,000 pounds (currency) for laying the rack railway and floated a company called The Rigi Railway & Co Ltd. Since capital was not forthcoming, Mr. Richard Wolley of Coonoor came forward to advance money on the condition that the Government of Chennai would entrust the contract to Mr. Wolley.

The agreement between the 2 was signed in 1886, and the company called The Nilgri Railway & Company came into being with a capital of Rs 25 lakhs. Lord Wenlock, Governor or Madras started the work on the line in August 1891, but the company was liquidated in 1894. Later, a new company was formed in 1894, and the work was completed in 1899. Madras Railway worked the line to start with. Though the Nilgris formed part of Coimbatore district, it was separated into an independent district in 1868. For a period of 13 years from 1830, it remained part of Malabar district. This was to prevent tobacco smuggling from Coimbatore. From John Sullivan's days to this date, more than 170 years have rolled by. Udagamandalam considered a sanatorium and hill resort by the Europeans, has come to be like any other district.