Following the French defeat by forces commanded by Arthur Wellesley at Vimeiro on August 21 the French forces under Jean-Andoche Junot found themselves almost cut off from retreat. The British command was then augmented by Harry Burrard and then Hew Dalrymple. Both were cautious men who rather than push the French were happy to open negotiations. Wellesey had sought to take control of the Torres Vedras and cut the French retreat but was ordered to hold. Following talks between Dalrymple and Francois Kellerman the convention was signed. 20,900 French soldiers were allowed to evacuate from Portugal with all their equipment and the British transported them to Rochefort, Junot arriving there on October 11.
The convention was seen as a disgrace back in England, a complete defeat of Junot had been transformed into the French escaping. The commanders seen as responsible - Wellesley, Burrard and Dalrymple, were recalled from Portugal to face a official inquiry. The inquiry was held in the Great Hall at the Royal Hospital at Chelsea from November 14 to December 27, 1808. All three men were cleared but while Wellesley soon returned to active duty in Portugal, Burrard and Dalrymple were quietly pushed into retirement and never saw active service again.