Maharaja Sir Tej Singh Prabhakar, KCSI (17 March 1911 – 15 February 2009) was the last ruling Maharaja of Alwar. A remotely related cousin of the previous ruler, Sir Jai Singh Prabhakar, he was selected by the British to rule Alwar, as Sir Jai Singh had been deposed by them for gross misconduct and for being anti British. Although Sir Tej (he had been knighted in 1943) proved to be an effective and popular ruler due to introduction of administrative reforms, he only ruled for a decade, from 1937-1947, before the coming of Indian independence in 1947.
In 1948, Alwar merged with other Eastern Rajputana princely states to form the Matsya Union; the union merged into that of Greater Rajasthan the following year. After 1948, Sir Tej retired to his Delhi residence, Alwar House, where he lived for the next six decades, visiting his former kingdom but rarely.
Sir Tej was formally stripped of his titles in 1971 as part of the mass derecognisation of the royal families. During the Indian Emergency, tax inspectors under the Indira Gandhi regime forcibly searched the Alwar palaces.
Sir Tej died at Alwar House, New Delhi on 15 February 2009, a month shy of his 98th birthday. He was cremated at Delhi. At his death, he was one of the last surviving princely rulers of the old Indian Empire and was the last living member of the Order of the Star of India. He was succeeded as Maharaja of Alwar by his grandson, Jitendra Singh.