NEW DELHI: From a central jail that could lodge only 1,273 prisoners to becoming south Asia's largest prison complex that houses over 17,500 inmates, Tihar's journey is ridden with controversies, brushes with high-profile prisoners and some memorable hangings.Friday's hanging of the four Nirbhaya gangrape-and-murder case convicts was a first in Tihar's history as never before four convicts were sent to the gallows at the same time.Currently, 10 death-row convicts are lodged in the prison, according to its website.In spite of being the largest prison in south Asia, Tihar does not have a hangman for years now and had to hire Pawan Jallad from Meerut for Friday's execution.Who had pulled the lever when Afzal Guru was hanged in 2013 is still a secret as the jail did not have a hangman even then.On Friday, Tihar witnessed a hanging after seven years. On February 9, 2013, Parliament attack convict Mohammed Afzal Guru (43) was hanged in Tihar. Guru, who was lodged in Jail No. 3, was executed at 8 am near his jail in a top-secret operation.Before Guru, the jail had also witnessed the hanging of another Kashmiri separatist leader, Maqbool Bhat, in 1984.In July 1985, Kartar and Ujagar Singh were hanged. They were hired by an eye surgeon to kill his wife after she came to know about his affair with his secretary. While the doctor and his lover walked free after spending 16 years in prison, Kartar and Ujagar Singh were hanged.Almost four years after that, Satwant Singh and Kehar Singh, convicted for the assassination of former prime minister Indira Gandhi, were hanged in Tihar.Satwant and Kehar Singh were hanged by executioners Kallu and Fakira.The hanging of the Nirbhaya case convicts was similar to the Ranga-Billa case. Ranga and Billa, convicted for raping and killing a teenage girl as also for killing her brother, were hanged on January 31, 1982.Tihar has also played a key role in the journey of many politicians and iconic figures.From anti-corruption crusader Anna Hazare to top industrialist Lalit Mohan Thapar, from "bikini killer" Charles Sobhraj to student leader Kanhaiya Kumar and former finance minister P Chidambaram, it has played host to many high-profile prisoners.Kumar has written about his stay in Tihar in his book, titled "From Bihar to Tihar", while Nobel laureate Abhijit Banerjee has also spoken about the time he had spent in Tihar while he was a student of the Jawaharlal Nehru University (JNU).Set up in 1958, Tihar Prisons was a village that had only one central jail with the lodging capacity of 1,273 prisoners in the beginning. With a gradual increase in its population, the prison complex now has nine central jails, which are overcrowded and house more than 17,500 inmates.Besides Tihar, there are two other central prisons in the national capital -- one in Rohini and another in Mandoli.Tihar is known as a model jail for its reformatory measures and "most-advanced security systems" with CCTV camera surveillance, a computerised prisoner management system (PMS), mobile jammers, X-ray scanners, hand held metal detectors (HHMDs), door framed metal detectors (DFMDs), latest weaponry, quick reaction teams (QRTs) and a multi-layer security system.In 1993, Kiran Bedi took charge as the inspector general of Tihar as part of a "punishment posting". She is still remembered for introducing certain reformatory measures, including Vipassana and meditation, for the inmates.The jail provides various correctional opportunities to the inmates such as vocational training, educational programmes through IGNOU and NIOS, computer courses, learning of traits at the Jail Factory and Tihar Baking School, spiritual courses, yoga, libraries, management of drug users, a drug de-addiction centre and HIV prevention.Tihar also has a brand of its own products, which are manufactured by the inmates. These include bakery products, handloom and textile, apparel, furniture, jute bags, herbal products etc.