--- - |2 Abstract This article offers a novel explanation of why some European democracies survived while others collapsed in pre‐WWII Europe, describing historical paths which ended with establishment of either self‐sustainable democracies or non‐democratic regimes in the interwar period. The historical path to self‐sustaining democracy began with the emergence, in the nineteenth century, of constitutional monarchies with executive power responsible to the monarch and freely elected legislatures. Such polities, without exception, became self‐sustaining democracies unless the transition was achieved through regime discontinuity (as in Germany in 1918). An intermediate stage in this historical process consisted of development, in some countries, of competitive oligarchy as a transitional stage between the constitutional monarchy and democracy. If a country's political history did not follow the above‐mentioned path, its initial democracy was susceptible to breakdown. This pertained to countries which transitioned directly to democracy or competitive oligarchy from absolute monarchy or other regimes lacking open‐outcome elections. - 'Journal of Historical Sociology, EarlyView. '