The Senior Scout section in the UK initially catered to boys roughly aged 15 to 18 and was intended to offer more advanced Scouting, greater responsibility, and a bridge toward adult leadership.
However, as the movement grew, it became clear that there needed to be a more clearly defined programme for young men entering adulthood.
In 1918, the Scout Association introduced Rover Scouts, aimed at young men aged roughly 18 to 25, with Rovering focused on service, outdoor adventure, and personal development, offering a more mature and flexible programme.
Rover Scouts were phased out in 1967 and replaced by Venture Scouts for ages 15 1/2 - 20.
November 1918
National Scouting Timeline