This cartoon refers to the invasion of Spain by Napoleon in February 1808, which led to the Peninsular War. There were fears that by controlling Spain, Napoleon was about to isolate Britain and partition Turkey. The Spanish revolted against Napoleon and the Duke of Wellington led a British expeditionary force to expel the French from Portugal and Spain.
A spider's web, at the centre of which is the spider Napoleon. On his back is written 'UNBOUNDED AMBITION', and he is eating the Spanish flies representing King Charles IV of Spain and his son Prince Ferdinand. Caught in the web are various flies, representing countries which have been defeated by Napoleon.
In the top right-hand corner the 'Pope Fly' struggles in the web, and says: "I'm afraid I shall be dragged in". The Russian fly says: "I declare I was half in until I made the discovery". The Turkish fly says: "I am afraid it will be my turn next". In the top left, the British fly, wearing a wig, says: "Ay you may look Master Spider but I am not to be caught in your web".