Peter Jones was the original Dragon who remained on the British television show Dragon's Den from its 2005 launch.
Jones joined the programme when the British version began and continued as a central member of its investor panel. He is an entrepreneur and investor whose interests have included technology, media, retail and consumer businesses. His tall stature and long tenure have made him especially identifiable to viewers.
The other original Dragons were Duncan Bannatyne, Simon Woodroffe, Rachel Elnaugh and Doug Richard. Each left the main panel at a different point, while later investors such as Deborah Meaden, Touker Suleyman, Sara Davies and Steven Bartlett brought new expertise and personalities.
Being an original Dragon is different from being the longest-serving surviving panel member. Jones satisfies both descriptions for the British programme, but the question asks specifically for the investor who carried on from the launch lineup.