Born a German prince in 1839 Prince Karl of Hohenzollern – Sigmaringen entered Prussian military service and fought in the 2nd Schleswig War against Denmark. When Romania's Prince Cuza was deposed Napoleon III recommended Prince Karl to the Romanians who were searching for a new elected ruler.
Travelling incognito the Prince entered Romania and was greeted by a large crowd in Bucharest in May 1866. Karl, now "Carol I" would rule for 48 years and helped Romania gain full independence, recognised by the Treaty of Berlin in 1878.
The early "classic" stamp issues of his reign were lithographed portraits, facing left, in various frames. The 1866 to 1870 designs show the Prince beardless, the 1871-72 stamps show him with a handsome beard, during 1872 perforating began & was quickly followed by a new design and the "classic" philatelic period was over!
The Stamps, in brief: 1866-67 Prince Carol Coloured Papers. Lithographed in Bucharest, the stones of 200 impressions were created from transfer blocks of six different types (the top right having a block of 4 blank spaces, thus creating the sheet of 200)
1868-70 Prince Carol "New Currency" issue. On the 1st January 1868 the currency changed from Parale to Bani and this new stamp issue was prepared. Lithographed in Bucharest the stones of 100 impressions were created from transfer blocks of eight different types with 5 blank spaces.
1869 Prince Carol WITHOUT Beard. Lithographed in Bucharest, the stones of 100 impressions created from transfer strips of four different types (the 50b had eight different types), often called the "International" issue.
1871-72 Prince Carol WITH Beard. Again, lithographed in Bucharest but the sheets of 100 created by vertical blocks of 10 different types.