Axis troops invaded Yugoslavia on 6 April 1941 and a few days later the independence of Croatia was proclaimed, with Zagreb as its capital. The first stamps of Croatia were issued less than a week after the invasion on 12 April 1941 with the overprinting of Yugoslavian stamps with further overprinting continuing until a pictorial issue began to appear on 15 August 1941, almost all of the 19 different values can be found in tete-beche pairs.
The rarest item of Croatian philately is the 1945 Storm Division miniature sheet, we warn collectors of excellent forgeries so please purchase yours from a trustworthy source. Russian troops and Yugoslav Partisans liberated the country during the early months of 1945 and stamp collectors can enjoy a diverse range of stamp issues rich in propaganda from that time. The Republic of Croatia began issuing stamps on 1 April 1991 and continues to this day.
We can recommend the extensive stamp listings in Stanley Gibbons Part 3 Balkans catalogue, also published by Michel in their Volume 3 Sud - Europa catalogue.