As a baritone-voiced brass instrument, the euphonium traces its ancestry to the ophicleide and ultimately back to the serpent. The search for a satisfactory foundational wind instrument that could support masses of sound above it took some time. While the serpent was used for over two centuries dating back to the late Renaissance, it was notoriously difficult to control its pitch and tone quality due to its disproportionately small open finger holes. The ophicleide, which was used in bands and orchestras for a few decades in the early to mid-19th century, used a system of keys and was an improvement over the serpent but was still unreliable, especially in the high register.
With the invention of the piston valve system c. 1818, the construction of brass instruments with an even sound and facility of playing in all registers became possible. The euphonium is said to have been invented, as a "wide-bore, valved bugle of baritone range", by Ferdinand Sommer of Weimar in 1843, though Carl Moritz in 1838 and Adolphe Sax in 1843 have also been credited. While Sax's family of saxhorns were invented at about the same time and the bass saxhorn is very similar to a euphonium, there are also differences[citation needed].
The "British-style" compensating euphonium was developed by David Blaikley in 1874, and has been in use in Britain ever since; since this time, the basic construction of the euphonium in Britain has changed little.