Complex sentence: Later legends from Alexandria, Egypt in the 12th century AD suggested that Alexander conducted reconnaissance missions, using a primitive submersible in the form of a diving bell, as depicted in a 16th-century Islamic painting.
Split into simpler sentences: Later legends from Alexandria, Egypt, in the 12th century AD suggested that he had used a primitive submersible for reconnaissance missions. This seems to have been a form of diving bell, and was depicted in a 16th-century Islamic painting.