The place was constructed to hold 5000 prisoners, and 500 men were employed by the War Office in 1808 upon its construction.

The first batch of prisoners were the victims of the battle of Vimeiro in that year.

Borrow's description of the hardships of the prisoners has been called in question by a later writer, Arthur Brown,[24] who denies the story of bad food and 'straw-plait hunts,' and charges Borrow with recklessness of statement.

'What could have been the matter with the man to write such stuff as this ?' asks Brown in reference to Borrow's story of bad meat and bad bread: which was not treating a great author with quite sufficient reverence.

Borrow was but recalling memories of childhood, a period when one swallow does make a summer.