There are many possible substitutes that share similar ranges and keys e.g. flute and oboe.

Maybe today. If we are talking about current day instruments you can get something close to an orchestra replacing the violins with something else (I personally think no, those would not be replacements because of their very different nature; you get a different thing when you have that kind of ensemble). Brass and woodwind instruments were not as developed as they are now.

If you look at clarinets, flutes and oboes from before the 19th century, you'll notice they don't have the key systems we are used to. This leads to limitations in range, difficulties controlling pitch, and difficulties to play fast or intricate passages. I understand woodwind instruments were made in one piece during the Renaissance (when orchestras started to develop), that creates difficulties in terms of pitch (having many of those instruments makes the problem much bigger).

Pre-valve brass instruments (before the last quarter of the 18th century) were even more limited. You would have serious limitations in the number of available notes. Trombones would give flexibility, but their agility and dynamic range (volume) is not comparable to that of violins.

The strings became organized and standardized sooner than the other families. There was a competing alternative, the family of the viol (bowed, fretted and stringed musical instruments). Yeah, it's easier to produce acceptably tuned pitches with frets, but being able to adjust pitch in real time is a strong point when you have several instruments playing at the same time (imagine the issues of variable pitch instruments vs. piano/harpsichords, but on a larger scale). I think viols were also quieter and less bright than violins. Fixed pitch instruments would be tuned in mean-tone by that time, which introduced some problems (limiting the usable intervals/scales/chords).

Why did people choose the violin?

The advantages of violins:

• Good range. A lot of available notes, without too many issues going from high to low notes or vice versa (wood winds still have issues with that, after a lot of developments). The range of the modern oboe is not comparable to the violin's. Brass instruments without valves were not doing good in this area (you needed several version of the instrument to be able to play more notes, that still happens: one player might use 2 versions of his instrument in one piece to be able to play the required notes without really complicating his life).

• Variable pitch. They can adapt to other instruments because they can change the tuning in real time. Yes, woodwind and brass could also do some of that. The woodwind and brass players can perform bloody miracles with their instruments!, but if your instrument is faulty you can have a bad time. Tools and techniques have improved, as well as designs for the instruments.

• Agility. Violins can play intricate passages, fast or slow. Woodwinds can do that to an extent, but if you remove their modern key systems, their agility gets limited (and tuning might also suffer).

• You can have REALLY long sustained notes with a violin, that is not terribly doable with woodwinds or brass (circular breathing was not a thing back then, as far as I know).

• Dynamic range. Violins can play real quiet AND reasonably loud. It is very difficult to produce quality notes at low volumes with brass instruments. Some registers of the woodwinds are problematic with low volumes.

You get a whole family of compatible, adaptable instruments, with a certain degree of standardization. You get good dynamic capabilities over a decent range. You can throw at them a lot of notes, fast or slow, without issues. You get a whole family of instruments with very compatible timbres (they blend well).

Now, I don't want to sound like I am bashing wind instruments/players. Modern devoted players are truly miracle workers. But those types of instruments were nowhere close to what they are now when the orchestra was appearing.

Brass instruments were (and still are) LOUD (woodwinds too). Musicians were not playing in massive concert halls back then (and music was not particularly loud in general). Brass and woodwinds work pretty well in open spaces (there are cannons in that video, which people generally enjoy; not the greatest performance, though).

I don't know when, but I can answer why.

It has to do with harmonic series. Violins are string instruments, meaning they have all the harmonics; even and odd. Wind instruments only have odd harmonics, and also have a stronger fundamental relative to the higher harmonics.

Without getting into the complexities of psychoacuoustics, this means we perceive many violins together as a warm, bright chorused tone, while wind instruments tend to be more resonant and piercing(especially when they are layered).

Instruments in this register are the most important overall because their fundamental is right in the middle of the human vocal range, the range which we evolved to be most sensitive in.

TL:DR(please don't hurt me for this, mods); it sounds better.

Others here have mentioned some of the practical reasons that the violins become the main instrument of the orchestra. There's definately a quetion of balance and ability to be heard in a performance environment (I'm reminded of the spoof, P.D.Q. Bach's concerto for various groups of instruments. "Think about the lute while you are listening to the bagpipes." )

That said I'm going to pull out my copy of "A History of Western Music Music" by Grout and Palisca (4th ed), to give some context:

In the early middle ages almost all insturmental music relates to singing and dancing. The vielle or Fiedel shows up in the Midieval period in various shapes and sizes.. some bowed as well as some using a crank. No stnadardization yet.. various designs. (p91-92)

The first publication we have for instrumental music shows up in 1511, as instrumental musicians began to gain in status. There begins to be descriptions of wood cuts for instruments happening also, around this time... The current proto-violin is the viol, and the main wind instrument is the recorder. (p284-286)

During the baroque period (1600-1750) composers begin to write for specific instruments rather than voice or any general instrument. This is also when the violins begin to replace the viols in italy, but the French focus on the viols.(p. 350) The great violin makers (Amati (1596-1684), Stradivari (1644-1737) and Guarneri (1698-1744)) make great violins in Italy and this is also an age of great string music in Italy (p 458).

At the end of the 17th century, instrumental music starts to become distinguished between songs played with 1 instrument per part (chamber music) and multiple instruments per part(orchestral music). Quoting directly from the book: "Beyond the use of basso continuo and predominance of the stringed instruments there was no common sandard that regulated either the makeup of an ensemble or the number of instruments to a part." (p 471)

From there the orchestra evolves, but from the start it appears to have a large number of stringed instruments. I do not find any explantion for why the predominance for strings, of which the violins become the upper register.

I've got some of my own thoughts for the preference and things I've been told, but I'm sure you can imagine some too.

This would probably be a better question for r/musictheory or r/musicology.