Rákóczi I György (1593 – 1648) was an important Hungarian nobleman who was Prince of Transylvania from 1630 until his death in 1648. During his influence, Transylvania grew politically and economically stronger.
He was a well-educated and tolerant, “modern” absolute ruler with good military skills and experience. As a strong and independent sovereign ruler of Transylvania, an area twice bigger as modern-day Hungary, he was indeed in a position to make a difference in the 30-Year-War.
I have summarized the events of his life in my article, you can read it on my page:
