He served in the Welsh Guards 1943-6 and was attached to Phantom, 1945. He did a brief spell of teaching as an Assistant Master at Eton College, 1948. His journalistic career began when he joined the Editorial Staff of the Daily Telegraph, a position he held from 1952 to 1960. He founded and wrote the Albany Column, 1961-97, for the Sunday Telegraph.
Rose was an award-winning writer, having won the prestigious Whitbread Book Award in the biography category in 1983 for his book, King George V. He shared that award with Victoria Glendinning, who won for her book Vita. He was appointed CBE in the 1997 New Year Honours.
In April 2005, days before the wedding of Prince Charles and Camilla Parker-Bowles, a British tabloid published that the couple were related, as ninth cousins, by way of the 2nd Duke of Newcastle-upon-Tyne. Rose said that, although the apparent familiarity between the two was not well established, a family connection was "perfectly factible".
- Who's in, who's out. The Journals of Kenneth Rose. Vol. 1 1944-1979. Edited by D.R. Thorpe (Weidenfeld & Nicolson, London 2018)
- Elusive Rothschild: The Life of Victor, Third Baron (2003)
- King George V (1983), awarded the Wolfson History Prize ISBN 0-297-78245-2
- Kings, Queens & Courtiers : intimate portraits of the Royal House of Windsor from its foundation to the present day (1985)
- Who’s Who in the Royal House of Windsor (1985)
- William Harvey : a monograph (1978)
- The Later Cecils (1975)
- Superior Person; a portrait of Curzon and his circle in late Victorian England (Weidenfeld & Nicolson, London 1969)
- Obituary: Kenneth Rose, The Daily Telegraph, 29 January 2014
- Daily Telegraph obituary.
- Who's Who 2012, London : A. & C. Black, 2012, 1964.