General Wellesley dispatches the South Essex, alongside Sharpe's Riflemen and the engineers of Major Hogan, to blow up the bridge at Valdelcasa, so as to protect the army's flank as they march. During an unnecessary action against the French ordered by Simmerson, Lennox was mortally wounded, and the King's Colour was lost. As a dying request, Lennox asks Sharpe to take a French Eagle, to erase the shame of losing their own standard. He died shortly after Sharpe promised that he would.
- In the Television movie, his rank is major.