the eariest examples of knitted cloth date from about 450CE (common era) but--footprints, preserved in what was mud, but became floor (inside of burial chambers in the pyramids) suggest knitting goes back long before the year 450.(1,000BCE or so)

it was an eygptian craft, and spread through out near east with rise of islam. it first appeared in europe in 1400's (or at least its first seen in artwork--there are almost no examples of knitted cloth that old!)
the oldest examples of knitted cloth are from spain (they got knitting from islamic presence there) mostly religious artifacts (hand knit silk gloves for a bishop, royal funeral pillows)

Knitting in the east (eastern knitting) is similar too, but not identical to European knitting (Western)
in various places, (russia, turkey,(all border countries betwen europe and asia (along the urals), spain (and all former spanish colonies)far east (indoneasia) there is a kind of knitting called 'combo knitting' (a combination of eastern/western styles)

eastern knitting sometimes uses needle that have standard point on end, and hook (crochet like hook) on the other end.
Knitting is faster than weaving as a way to make clothing. it is natural stretchy, so 1 size fits many. and its portable. the tools to knit are much cheaper than a loom.

Until about 150 year ago, it was more common for the poor (working class) to wear knit garments.
(anyone who could, wore tailored clothes, (and clothes for rich were often very form fitting, and restricted movement..but then the rich don't need to be able to lift thing, or carry things, or pitch them (over head) or other movements)
but there was an exception: fancy, silk lace things-- King charlie went to his beheading wearing a silk 'undershirt' (you can see a facsimile at wax musuem!) the stitch pattern used on the shirt is now called king charles.

starting in about 1850, the rich discovered leasure activites like boating and tennis, etc, and they started to wear knit clothes (since they are superior for ease of movement.) sailors had long worn them, along with the poor.
since then, sweaters (and knit clothing) have become more and more common, not just for sports, but for general use.
(knitting machines (or jenny's) are as old as power (water power) looms. but hand knitting was still often cheaper, (since it could be done for such a small investment of money! (vs the large investment in knitting jennies that knit 'fabric faster (but it took longer to convert into finished clothing than hand knitting)