Norway - Norge

Source

The first postage stamp of Norway was issued in 1855, and depicted the Coat of arms of Norway.

However, in 1871, Norway introduced its first stamp with a posthorn design; stamps of this type, with periodic redesigns, have been in use ever since - making it one of the longest-lasting stamp designs in history and has been around for an amazing 142 years (in 2013).


Source

To quote the Philatelic Database: The posthorn stamps have survived the dissolution of Norway’s union with Sweden, two world wars, a long period of German occupation and several currency reforms.



Images of Norwegian stamps.

Hungary, Austro-Hungarian Empire

Hungary was an integral part of the Austro-Hungarian Empire from 1867 until  the end of WWI in 1918.  The House of Habsburg shared power with the separate Hungarian government, and there was a dual constitutional monarchy. Franz Josef I was both the Emperor of Austria, and the King of Hungary. The two capitals of the Monarchy were Vienna in Austria, and Buda (joining adjacent Pest - 1870) in Hungary.

During 1850-1871, the stamps of Austria were also used in Hungary.  But in 1867, the Hungarian Post became independent. The King of Hungary, Franz Josef I, naturally, was featured on the first 1871 Hungarian stamp issue.

Italy Monarchy

In 1850, Count Camillo Cavour drafted a report to the Piedmont Chamber of Deputies proposing postal reform along the lines of that which had been adopted in several European states, and including postage stamps, for which a new word - francobollo - was coined. The reform became law in November, and went into effect 1 January 1851.

After some casting around for expertise in the newfangled art of stamp printing, the government settled on the house of Francesco Matraire in Turin. Matraire produced stamps with an embossed profile of Victor Emmanuel II.

Matraire of Turin also produced a distinctive 15c. stamp, the first designed specifically for the new kingdom, hence the inscription FRANCO BOLLO ITALIANO (Italian Postage Stamp). The stamp was lithographed pending receipt of a supply of stamps printed by De La Rue. Two versions of the stamp exist. The first ‘C’ in the bottom inscription is almost closed, while in the second the ‘C’ is open and the line below ‘Q’ of QUINDICI is broken.

Sweden - Sverige

The Treskilling Yellow
Source: Wikipedia

Sweden issued its first postage stamps on 1 July 1855, a set of five values denominated in skilling banco. These stamps depicted the coat of arms(Vapentyp), were inscribed "SVERIGE", as have been all subsequent Swedish stamps, and were perforated. Sweden was therefore the first country to issue perfed stamps from it's first stamp.

A printing error resulted in the Treskilling Yellow, a unique stamp that is currently the highest-priced in the world. Due to a printing error, this stamp is printed on yellow colored paper (meant for the eight skilling stamp of the same set) instead of the usual green color (used for the three skilling stamp). One copy of the yellow error variety of this stamp was found in 1885 by a young Swedish boy in his grandfather's collection. It is a one-of -a- kind rarity, as no other copies have been discovered to date. In 1996 the stamp was sold to an anonymous collector for $2.3 million at auction.