Here is everything we know so far about HBO’s “Harry Potter” TV series.

John Lithgow will play the Hogwarts headmaster in the HBO show, with Paapa Essiedu filling the role of Severus Snape.

It was then that Rowling began writing the first Harry Potter book, which was eventually published in 1996.

The show comes nearly 30 years after J.K. Rowling published “Harry Potter and the Sorcerer’s Stone,” which was adapted into a film directed by Chris Columbus in 2001. In total, the original ...