Divine Right

The big gotcha first: legitimacy is a free base-game mechanic, but this achievement only fires with Legends of the Dead owned and enabled - plenty of players have sat at max legitimacy wondering why nothing popped. With the DLC on, the wiki's designer build (Virtuoso Arbitrator, Just, Diplomat and Sayyid, age 33) spawns you at legitimacy level 4 with half the bar to 5 already filled; take the Diplomacy lifestyle with the Writing History perk and top up the rest with prestigious marriages and well-hosted activities.