Until then the term denoted a functional position rather than a formal rank, being the title bestowed on the senior officer of a fleet of at least two naval vessels comprising an independent (usually ad hoc and short-term) command.

The previous broad red and blue pennants were abolished in 1864 along with the coloured squadrons, the commodore of the white's broad pennant with the Cross of St George remained as the command flag for commodores first class, who wore the same sleeve lace as rear admirals.

The white broad pennant with a red ball was introduced as the command flag for commodores second class.

During World War I the title of "Commodore (T)" was the officer who commanded torpedo boat flotillas.

[3][4] From 1570 to 1864 the Royal Navy was divided into coloured squadrons which determined an officer's career path.