From their first game against Czech side Banik Ostrava to reaching the final in 2006, we’ve picked out 21 iconic pictures from the Teessiders’ European adventure. Scroll down and flick through our picture gallery to look back on some of the most memorable moments.
5. Boro dumped out by Sporting Lisbon
After progressing through the group, Boro are knocked out of the competition by the Portuguese side. Photo: Gary M. Prior
6. Remember this away kit?
Boro come through a two-legged qualifier against Greek side Skoda Xanthi at the start of the 2005/06 campaign. Photo: Milos Bicanski
7. Hasselbaink on target in Switzerland
A solitary goal from Jimmy Floyd Hasselbaink gets Boro off to a winning start in their group. Photo: Ross Kinnaird
8. Tricky conditions
Szilard Nemeth challenges for possession as Boro are held to a goalless draw away at AZ Alkmaar. Photo: Mark Thompson