Short answers, pulled from the story.
The earliest known visual evidence of the violin family appears carved into the cupola of the Madonna dei Miracoli church in Saronno, Italy, in the year 1535. Angels depicted in the stone sculpture hold instruments that clearly resemble the modern violin, complete with f-holes and a scroll. This image predates the first written descriptions of the instrument by over two decades.
The oldest surviving example of these royal commissions is known simply as the Charles IX and was ordered by the French king Charles IX in 1560. Andrea Amati constructed 24 violins for him, and the oldest surviving example now rests in the Ashmolean Museum of Oxford.
Antonio Stradivari worked from 1644 to 1737, and Giuseppe Guarneri del Gesù was active until 1744. The Stradivari family produced over 1,100 instruments, yet only a fraction survive today, and those that do command prices that dwarf most other collectibles.
The strings are tuned in perfect fifths to G3, D4, A4, and E5, creating a range that spans over four octaves. The body is typically constructed from spruce for the top plate and maple for the ribs and back, with the maple often featuring a distinctive striped figure known as flame or tiger stripe.
A typical bow measures about 74 centimeters and weighs approximately 60 grams, with the hair traditionally sourced from the tail of a grey male horse. The friction between the rosin-coated hair and the string causes the string to vibrate, producing a sustained tone that can be shaped by the player's control of speed, pressure, and position.
In India, the violin is tuned differently, often in a cross-tuning of G3-D4-G4-D5, and is played seated on the floor with the scroll resting on the side of the foot. This is a stark contrast to the Western posture of holding the instrument under the chin.