Complex sentence: Nelson's grandson Tupua Tamasese Tupuola Ta'isi Efi was the third prime minister of Western Samoa and from 2007 to 2017, he was, as Tuiatua Tupua Tamasese Ta'isi Efi, the Head of State of Samoa.
Split into simpler sentences: Nelson's grandson Tupua Tamasese Tupuola Ta'isi Efi was the third prime minister of Western Samoa and from 2007 to 2017. He was, as Tuiatua Tupua Tamasese Ta'isi Efi, the Head of State of Samoa.