system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Who discovered magic? When? How was it institutionalized in a network of magic schools?

Basically just feed me HP lore until I puke.
gpt
Cramming for your History of Magic final, eh? Well, here's the basics.

Magic has been around for about as long as people. 

Ancient Times:

Magical folk were more or less an accepted aspect of society in Ancient Greece and Rome. A lot of religious and political figures were witches/wizards, or had them as advisers. Muggles and Magic folk more or less got along at this time. This is why there are lots of stories from those days involving magic, prophets, seers, that sort of thing. The Patronus Charm and the first horcrux were invented in Greece. Ollivander's ancestors came to England with the Romans, and set up shop. (382 B.C.)

Medieval Times:

This is when things started to go bad. Muggles started burning witches and wizards at the stake. Wizards start to go into hiding. Hogwarts was founded in 990 A.D., specifically to educate magical kids in seclusion, away from muggles. Merlin was also active at this time, and while we don't have a lot of information about him (besides the obvious stuff even Muggles know) he did create the Order of Merlin, whose goal was to promote muggle rights and cooperation between muggles and wizards. Beedle the Bard wrote his stories, including the Tale of the Three Brothers, around this time. Pretty sure Quidditch was invented around this time as well, don't have a date.

Not-quite-modern era
In 1692, The Statute of Secrecy, which officially separated the magical and muggle world, was made into International law. In 1707, Ministry of magic founded. There was a goblin uprising in the 1700's, probably not the first, definitely not the last. Dumbledore is born, 1881. Tom Marvolo Riddle is born, 1926. Dumbledore and Grindelwald battle in 1945. 

And, of course, Harry Potter, born 1980. From then on, the best way to learn about Wizards in the modern era is to read the biographical account of his life. Even the muggle version has plenty of great information about modern witches and wizards.