This is a study of the formation and 1929 electoral campaign of the German-Swedish bloc, an alliance between two of Estonia's national minority parties. Its success shows that by the end of the 1920s, the two groups' shared interests were able to transcend even entrenched historical divisions. Nevertheless, the Swedish party's controversial collaboration with "the Barons" stirred debate and Estonian parties tried to use the controversy to split the Swedish vote. The allies responded by attempting to attract voters from other ethnic groups, including Estonians. The article highlights the importance of minority-to-minority relations in interwar parliamentary democracies and emphasises the significance of minority parties appealing to diverse voter groups.