How was Gulliver made a prisoner in the country of Lilliput?

After swimming ashore and passing out from exhaustion, Gulliver awakens and finds himself unable to sit up or move at all. His "Arms and Legs were strongly fastened on each side to the Ground; and [his] Hair, which was long and thick, tied down in the same manner."

Later, the Lilliputians drug his food and move him to the capital (bound to a large platform) while he is asleep.