The first known metal trumpets can be traced back to around 1500BC. Silver and bronze trumpets were discovered in the grave of King Tut in Egypt, and other ancient versions of the instrument were found in China, South America, Scandinavia, and Asia. Since most inventions spawn from earlier forms, there's also good reason to assume that people have been blowing into objects to create sounds for even longer than that. For example, some civilizations blew into an animal horn or conch shell to produce a sound.
Many of these earlier examples were not used to make music as we know it today. Typically, they were used for religious and military purposes, which historians have pointed out in major religious writings and other historical records. In medieval times, for example, trumpeters were highly guarded by military units, since they were crucial to relaying instructions over great distances. In modern times, the "bugle" is still used by militaries, but mainly for paying respect to its past use.
Instrument design, as well as metal making, improved tremendously over the Middle Ages and the Renaissance, which made these "natural trumpets" more suitable for creating actual music. However, these trumpets did not have valves and could only produce a small amount of notes. Also, changing the key meant that you had to change different pipes on the horn. The natural trumpets peak of popularity was during the Baroque area; but in recent years it has seen somewhat of a resurgence. In fact, many examples of the "natural trumpet" can be found easily on You Tube.
Due to its limited amount of notes, usage of the natural trumpet started to fade during the Classical and Romantic periods. By the 1800's, instrument improvements, such as keys and valves, led to its chromatic use. Following its capability of playing any note needed by the composer, it redeemed its rightful place as a dominant musical instrument.
During the twentieth century, the concept of "Pop Music" emerged, and although popular music has always existed in one shape or another, this area of sound recordings meant that songs could become "hits" by reaching many people at once. Early on, many instruments did not translate well to tape. However, the trumpet proved to be an exception, and quickly became a standout favorite, thanks to its clear focused sound. Virtuosos like Louis Armstrong brought the trumpet to the forefront of popular music during the 1930's, and its popularity continued for decades, from Dizzy Gillespie to Miles Davis.
The trumpet has soldiered on throughout history, and today it can be heard in all kinds of musical styles, from rock to classical. Remember, your trumpet is much more than a musical instrument. It's been a clarion call to humanity for centuries.