He began contributing episodes regularly to the adventure series Knight Errant before becoming that programme's Story Editor in 1959. Holmes found himself working almost exclusively in television drama after 1957. In the late 1950s he worked for a time writing and editing short stories for magazines, before receiving his first break in television when he contributed an episode to the famous medical series Emergency - Ward 10 ( 1957).

He also filed reports for the Press Association, which could be syndicated to a variety of sources, such as local or foreign newspapers. He quickly found work writing for both local and national newspapers, initially in London and later in the Midlands. To this end, he taught himself shorthand in his spare time and eventually resigned from the Police force. When giving evidence in court for prosecutions against offenders, he would often note the excitement and frantic work of the journalists reporting on the cases, and decided that he would like to do similar work. It was whilst serving at a Police officer that Holmes first began to develop an interest in writing as a career. He trained at the elite Hendon College, graduating the top of his year and joining the Metropolitan Police in London, serving at Bow Street Police Station. Soon after the end of the war, Holmes returned to England and left the army, deciding to join the police. The fact that he lied about his age to get into the army was discovered at his commissioning, but apparently the only reaction was by a general who praised him, adding that he had done the same thing himself. He rapidly earned a commission, and as such became the youngest commissioned officer in the entire British army during the Second World War. In 1944, at the age of just sixteen, Holmes joined the army, fighting with the Queen's Own Cameron Highlanders regiment in Burma.

Robert holmes script writer