Complex sentence: Charles Christian Reisen (1680--15 December 1725), gem-engraver, born in 1680 in the parish of St. Clement Danes, London, was the eldest son of Christian Reisen, a goldsmith, of Trondheim in Norway.
Split into simpler sentences: Charles Christian Reisen (1680--15 December 1725) was an English gem-engraver. He was born in the parish of St. Clement Danes, London, was the eldest son of Christian Reisen, a goldsmith, of Trondheim in Norway.