How do dictators prepare for succession? Scholars have studied the determinants of succession, but we know little about the mechanisms, including elite management, of how succession occurs. We argue that incumbents prepare for succession by building a power base, of elites outside their inner circle, for their preferred successor; this helps the successor stabilize the regime. We test the argument by examining preparations for succession in the prominent but puzzling case of North Korea under Kim Jong Il, leveraging the plausibly exogenous shock that Kim suffered—a stroke—that caused him to prepare for succession. Quantitative analysis of 1,573 leadership events under Kim between 1994 and 2011, with original biographical data on 230 North Korean elites, supports the argument. Qualitative evidence of elites’ roles after Kim’s death is consistent with the argument’s logic. Rather than being atypical, as North Korea is often portrayed, the findings apply to other personalist autocracies.