Complex sentence: Cape Ann was first mapped by the explorer John Smith, although he had given it the name "Cape Tragabigzanda", after his owner in Constantinople when he was enslaved as a prisoner of war by the Ottoman Empire.
Split into simpler sentences: Cape Ann was first mapped by the explorer John Smith. He had given it the name "Cape Tragabigzanda", after his owner in Constantinople when he was enslaved as a prisoner of war by the Ottoman Empire.