 Complete the following phrase:  In 1816, he received a promotion to Privy Councillor and, in 1817, became a member of the Senate. He also served on various commissions, including oversight of the construction of Saint Isaacs Cathedral and directing operations for the Imperial theaters. In 1826, he was appointed to the Supreme Criminal Court charged with prosecuting the Decembrists. In 1832, he became an Imperial Steward. After receiving two more promotions, he was stripped of his ranks, following the disastrous 