Complex sentence: On 20 January 1807 Soane was made clerk of works of Royal Hospital Chelsea, he held the post until his death thirty years later, it paid a salary of £200 per annum.
Split into simpler sentences: On 20 January 1807 Soane was made clerk of works of Royal Hospital Chelsea. He held the post until his death thirty years later; it paid a salary of £200 per annum.