THE TROMBONE HISTORY IN VERY SHORT LINES:
( I am working on a bigger text at the moment, but this will do to begin with).





TIMELINE OF THE TROMBONE
ca. 1450 The trombone developed out of the slide trumpet.
The italian term was tromba, and adding a "a" / "one" to the end means as much as "big trumpet".
The instrument was made to add more fundament to the music, where the slide rumpet couldn't play.
The invention was a big leap towards playing more easy, because of the ingenious "slide".The trombones where known as Sackbuts


ca. 1540 The earliest surviving instruments date from the mid-16th century. 
Three types were used in this period:
an "ordinary" Tenor sackbut in Bb (gemeine-posaune),
an alto sackbut in Eb (mittel-posaune),
nd a bass sackbut in F (grosse-posaune) also known as quart- or quint-posaune, indicating the intervallic distance from the Bb gemeine-posaune. 
rombones in other keys were sometimes made as well.


ca. 1600 The same pattern continued with the addition of a contrabass instrument (octav-posaune),although it is unclear to what extent it was actually used.
Sackbuts were regularly used in all types of ensemble, from large court bands to small mixed consorts where it could blend with the softest instruments


ca. 1685 A small trombone pitched an octave above the tenor made its appearance in central Europe and was used mostly for playing chorale melodies in trombone ensembles.
There is no "title" anywhere, but it would be something like
Sopran sackbut in Bb (hohe posaune).This instrument never really survived the times. maybe because it was too hard to play.
It's function was later replaced by the cornetto.


ca. 1750 Several composers write trombone concertos for alto trombone:
G.C Wagenseil, L.Mozart, Michael Hayden & J.G.Wagenseil to name a few.


ca. 1780 The trombone began to be used in opera to lend dramatic effect to certain scenes, as in Mozart's Don Giovanni and Magic Flute.


1800-1850 During the early 19th century, composers increasingly called for three trombones in the orchestra.  Parts were included in Beethoven's 5th and 9th symphonies. 
The normal trio of Eb alto, Bb tenor, and F bass began to give way.
The alto trombone was retained (as it is today in central Europe) for parts requiring a high tessitura and light balances.


ca. 1828 The new valve trombone was introduced, and, while it received acceptance in bands, it was little used in orchestras.


1839 C.F.Sattler of Leipzig introduced the first Bb-F trombone.  The change to the F attachment was (as it is today) made by a rotary valve.


ca. 1850 From the mid-19th century, German trombones became larger in bore and bell and took on their traditional wide-bow construction.  French trombones of the Courtois type retained a smaller bore and bell taper.  Large bass trombones in F or Bb/F became the rule in German sections.  A smaller bass trombone in G was used in brass bands and orchestras in England for almost a century.


1876 A contrabass trombone in BBb with a double-tubed slide was constructed for Wagner's Ring.


1890-1920 During these years, small-bore Courtois-type trombones were popular in France, England, and in bands in the U.S.  Players in American symphony orchestras preferred large-bore German instruments and these influenced the development of the modern American symphonic trombone (which combines the best features of French and German instruments).


ca. 1939 The trombone gained widespread popularity through the influence of Jazz-bandleaders, such as Tommy Dorsey and Glenn Miller. 
Tommy Dorsey, in particular, left his mark on all trombonists for his remarkable control and smooth legato.


ca 1950 American-type orchestral trombones became standardized throughout the world, in some cases (as in England) displacing traditional small-bore instruments, in Germany and Austria, but German trombones continued their independent line of development.


ca. 1965 Hans Kunitz invented the in-line independent double-valve large bass-contrabass trombone, tuned F/C-D-Bb.


Present Large-bore tenors with and without F attachment and in-line double-rotor bass trombones are used in orchestras and bands today.  While small-bore trombones are rare, medium and medium-large bores are widely used by students and in the jazz and recording fields.  Alto trombones are used for certain repertoire (particularly in Germany).  Modern versions of traditional German trombones are preferred in Central Europe.  The valve trombone is now only found in jazz, where it is an important solo instrument.