Complex sentence: He remained an employee and later a partner of Boulton & Watt until the 1830s and his reputation as an independent inventor has tended to be obscured by the reputations of those two men and the firm they founded.
Split into simpler sentences: He remained an employee and later a partner of Boulton & Watt until the 1830s. His reputation as an independent inventor has tended to be obscured by the reputations of those two men and the firm they founded.