You might've never heard of Gerhard Groote, he's kinda a forgotten early reformer.
Groote was born in a small town in the Netherlands in 1340. He lived in the worst of the Black Death and in the middle of the Hundred Years' War. He was involved in the scholastic movement, so he was a very highly educated man. When he was 10 the Black Plague swept through his town and killed both his parents. So he inherited his parents money, used it for partying and traveling and became a spoiled brat.
On one of his travels, he met an augustinian monk who was simply preaching the Gospel and Groote stayed and listened to this monk, and he changed drastically from that day on. He converted to Christianity that day and experienced, in his own words "a melting of his heart".
He returned to his hometown and started reading books from is big library where he collected from his trips. For months he did nothing but read books. He tried to go to church but he was annoyed with all the heresy and corruptions of the church, so he decided to stay at home. He was the first one to notice all the corruptions in the church, and it is his teaching later in life that made other people question The Bible.
During his conversion, the Black Death swept through his town again, but he survived and since he changed he started taking in some orphaned boys and gave 'em food and water. He started teaching them about the Gospel and how to read and write. During the day he made them copy some of the great classic books from his library taking some breaks, where Groote would give them oral lessons. He bought the house next door and set up the same kind of school but for girls.
He traveled and preached and soon had some followers. So he built more schools and his graduated students would become teachers in these schools. He named the schools "Brethren of the Common Life" because not only did they share a common life but also common things like reading and writing, plain teaching, and hard work.
Then the Black Death swept through his town a third time, and this time it killed him, in 1384. He didn't really leave any instructions for after his death, but these schools continued for another 150 years. Many famous people learned from these schools, such as: Thomas a Kempis, Martin Bucer, Ulrich Zwingli, John Knox, John Calvin and Martin Luther and learned from the Brethren of the Common Life school.