Peter Jones was the original Dragon's Den investor who remained on the main panel after all the other launch Dragons left.
Jones joined the British programme when it began and continued as a regular Dragon while the rest of the original investor group changed over time. This made him the only launch-panel investor to remain a continuing member of the main panel across the programme’s successive line-ups.
The first group also included Duncan Bannatyne, Rachel Elnaugh, Simon Woodroffe and Doug Richard. Their departures happened at different points, so the panel evolved rather than changing all at once. Later Dragons included investors such as Deborah Meaden, Theo Paphitis, Kelly Hoppen and Touker Suleyman.
Peter Jones is sometimes described simply as the longest-serving Dragon, but the more precise fact is that he is the sole surviving member of the original regular panel. That distinction separates his tenure from the careers of the other launch investors.