Robert Maximilian Rainey-Robinson was born in April 1861 at Secunderabad, India, the second son of Major-General Arthur Jacob Macan Rainey (Madras SC) and Caroline Susannah Rainey (nee Robinson) eldest daughter of the Rev. William Robinson, Rector of Bovagh, County Londonderry.
Educated at Charterhouse and Cheltenham, entered Sandhurst in September 1880. He was commissioned in to the Indian Army under the surname Rainey and later in 1897 assumed the name Rainey-Robinson. First as Second Lieutenant in the 24th Foot (South Wales Borderers) 1881, as Lieutenant in the 1st Madras Pioneers 1882, 72nd Punjabis 1890 and 62nd Punjabis 1902-1909.
He served with the Zhob Valley Expedition in 1884. Served with the Burmese Expedition in 1885-89 (mentioned in despatches, Medal with two Clasps). Conducted the Chin Bok operations in 1889-90 as Commandant of the Chin Levy Military Police (mentioned in despatches, Clasp). Served with the Manipore Expedition in 1891 (Clasp); and in the operations in Burmah in 1891-92 as Staff Officer to the Baungsh Column.
On the 22nd January 1901 he was promoted to rank of Major whilst serving with 62nd Punjabis.
On the 1st June 1902 he was granted temporary rank of Lieut.-Colonel whilst serving as Commandant in the Indian Army, Commading the 62nd Punjabis.
He married Alice Frances Hildebrand,eldest daughter of Arthur Hedding Hildebrand CIE, in 1903 in Wiltshire. They later had 6 children; Margaret (Peggy), Elizabeth (Betty), Alice Helen, Monica Anne, Catherine and Frances Mary Rainey-Robinson.
On the 11th June 1907 he was granted the rank of Brevet Colonel.
He was invested as a Companion, Order of the Bath C.B. in 1912 (London Gazette 14th June 1912).
On the 14th February 1913 he retired, on half-pay, from the Indian Army.