High Quality Content by WIKIPEDIA articles! Robert de Cotte (1656 – 15 July 1735) was a French architect-administrator, under whose design control of the royal buildings of France from 1699, the earliest notes presaging the Rococo style were introduced. First a pupil of Jules Hardouin-Mansart, he later became his brother-in-law and his collaborator. After Hardouin-Mansart`s death, de Cotte completed his unfinished projects, notably the royal chapel at Versailles and the Grand Trianon.