Since the overthrow of absolute monarchy in 1932, Thailand’s political history has conventionally been interpreted as a long series of popular struggles for representative democracy and against authoritarian military rule. Yoshinori Nishizaki argues that this history is better understood as a continual struggle by elite political families for and against “dynastic democracy”—characterized by the transmission of power between members of select ruling families. Thailand has experienced no fewer than twenty two coups over the course of the past century, and Nishizaki shows that family-based contests for power underlie that tumultuous politics. Drawing extensively on Thai-language primary sources, Nishizaki traces the intricate blood and marriage connections among Thailand’s political families. These families fall into two categories: influential commoners who have held parliamentary seats since 1932 and form the core of Thailand’s dynastic democracy; and upper-class citizens who are related to the royal family either by kin or by ideological alignment, and who have repeatedly challenged political transitions with coups and constitutional changes, among other manoeuvres. Nishizaki illustrates how a broader democracy in Thailand has been consistently stifled, to the detriment of ordinary citizens. Dynastic Democracy fleshes out a widely acknowledged yet heretofore empirically unsubstantiated facet of Thai political history—that in Thai politics, family matters.