Short answers, pulled from the story.
Trombone derives from the Italian tromba, meaning trumpet, combined with the suffix -one, meaning large. The name translates as large trumpet, a description of the instrument's physical relationship to its smaller brass relative.
The Renaissance-era instrument was called the sackbut in English, first recorded as shakbusshe in English court documents in 1495. The Spanish form sacabuche appears as early as 1478, and the French saqueboute in 1466. When the instrument returned to common use in England in the 18th century, Italian cultural dominance meant it was adopted under its Italian name, trombone.
Claudio Monteverdi, Heinrich Schutz, Giovanni Gabrieli, and Andrea Gabrieli all wrote for the instrument in the early 17th century. Christoph Willibald Gluck became the first major composer to use the trombone in an opera overture, in Alceste in 1767. Johann Sebastian Bach used a choir of four trombones to double the chorus in cantatas BWV 2, BWV 21, and BWV 38.
The earliest known independent trombone concerto is probably the Concerto for Alto Trombone and Strings in B-flat by Johann Georg Albrechtsberger, dating to 1769. Earlier Classical composers had written concertante movements for alto trombone within divertimenti and serenades, such as Leopold Mozart's Serenade in E-flat from 1755 and Michael Haydn's Divertimento in D major from 1764.
The modern trombone uses seven chromatic slide positions, first described by Andre Braun around 1795. Each successive position outward lowers the pitch by one semitone when played in the same partial. Extending the slide lengthens the tubing and lowers the pitch; the lowest standard note on a tenor trombone is E2, a tritone below B-flat.
Christian Friedrich Sattler was the most influential designer. He introduced a significantly larger bore, described as the most important innovation since the Renaissance, as well as the bell garland, wide bell flare, and snake decorations. He also developed the valve attachment in the late 1830s, adding roughly three feet of tubing to lower the pitch from B-flat to F. His tenor-bass trombone was championed by the Leipzig professor Karl Traugott Queisser, spreading its use through German and Austrian orchestras in the 1840s.