Complex sentence: Thomas' uncle James died in 1764, and his widow Jane probably provided both the funds and accommodation which allowed Thomas to attend school in London; in 1765 or 1766 he started at the Soho Academy.
Split into simpler sentences: Thomas' uncle James died in 1764, and his widow Jane probably provided both the funds and accommodation which allowed Thomas to attend school in London. In 1765 or 1766 he started at the Soho Academy.