A new device for granting assent was created during the reign of King Henry VIII. In 1542, Henry sought to execute his fifth wife, Catherine Howard, whom he accused of committing adultery; the execution was to be authorised not after a trial but by a bill of attainder, to which he would have to personally assent after listening to the entire text. Henry decided that "the repetition of so grievous a Story and the recital of so infamous a crime" in his presence "might reopen a Wound already closing in the Royal Bosom". Therefore, parliament inserted a clause into the Act of Attainder, providing that assent granted by Commissioners "is and ever was and ever shall be, as good" as assent granted by the sovereign personally. The procedure was used only five times during the 16th century, but more often during the 17th and 18th centuries, especially when George III's health began to deteriorate. Queen Victoria became the last monarch to personally grant assent in 1854.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): Who was the last monarch to grant assent personally?
Queen Victoria