Tzar Boris as engine-driver (Bulgaria 1939)

Stamp Tzar Boris as engine-driver it reflects the thematic directions:

Railways - Transportation system made up of metal rails which is designed to allow trains to maneuver on the tracks from one location to the next.

King is the title given to a male monarch in a variety of contexts. The female equivalent is queen regnant (while the title of queen on its own usually refers to the consort of a king). In the context of prehistory, antiquity and contemporary indigenous peoples, the title may refer to tribal kingship. Germanic kingship is cognate with Indo-European traditions of tribal rulership (c.f. Indic rājan, Gothic reiks, and Old Irish rí, etc.) In the context of classical antiquity, king may translate Latin rex or either Greek archon or basileus. In classical European feudalism, the title of king as the ruler of a kingdom is understood as the highest rank in the feudal order, potentially subject, at least nominally, only to an emperor (harking back to the client kings of the Roman Empire). In a modern context, the title may refer to the ruler of one of a number of modern monarchies (either absolute or constitutional). The title of king is used alongside other titles for monarchs, in the West prince, emperor, archduke, duke or grand duke, in the Middle East sultan or emir; etc. Kings, like other royalty, tend to wear purple because purple was an expensive color to wear in the past.

A locomotive is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight trains.