The party was established on 13 November 1960[1] by the merger of the Republican Party of Dahomey (PRD) led by Sourou-Migan Apithy, the Dahomeyan Democratic Rally (RDD) led by Hubert Maga and the National Liberation Movement (MLN) led by Jean Pliya and Albert Teveodjré.
[2] The PRD and the RDD had previously merged in 1958 to form the Dahomeyan Progressive Party, but had split the following year.
[3] Changes to the electoral system made by Maga allowed the PDU to win all 60 seats in the Dahomeyan parliamentary election, 1960.
The following year, the main opposition party, the Dahomeyan Democratic Union, was banned and its leader Justin Ahomadégbé-Tomêtin imprisoned.
[4] As a result, the PDU became the sole legal party in the country.