After the coup d'etat of 29–30 April 1918 and the accession to power of Hetman P. Skoropadskyi, the People's Republic was abolished, and Ukraine was proclaimed the Ukrainian State. The Ukrainian postal administration had considerable stocks of such stamps. In order to use them and to prevent similar stamps from other regions from entering circulation—which would have harmed the Ukrainian treasury—on 20 August 1918 the Hetman's Ministry of Posts decreed that the Ukrainian state coat of arms, the trident of Saint Volodymyr, be overprinted on all available stocks of Russian stamps.
Carrying this out in a centralized manner under civil-war conditions was impossible. Therefore, the overprints were applied by local authorities simultaneously across all postal districts, using whatever technical means were available, often by hand. This resulted in a great variety of overprint types and graphic styles.
Research has identified 52 main types of tridents, 68 varieties, and 13 printing errors—133 principal varieties in total. The overprints were made in six postal districts: Kyiv, Poltava, Kharkiv, Katerynoslav, Odesa, and Podillia.
Ukrainian provisional postage stamps began to be forged as early as late 1918 in southern Ukraine, and later counterfeiters abroad produced forgeries as well. They forged overprints and postmarks and even created non-existent denominations, so-called "fantasy" issues. The Union of Philatelists of Ukraine in Germany successfully detected these forgeries.