"In the Muggle world," Rowling explained, Potter is a surname that denotes a man who creates pottery. The Potter family can trace their surname back to an eccentric twelfth-century wizard, Linfred Stinchombe, who was known by his nickname "the Potterer."
"His reputation as a well-meaning eccentric served Linfred well, for behind closed doors he was able to continue the series of experiments that laid the foundation of the Potter family's fortune," Rowling wrote, noting historians credit Linfred for the Pepperup Potion and Skele-grow, which Harry memorably had to endure in The Chamber of Secrets. "His sales of such cures to fellow witches and wizards enabled him to leave a significant pile of gold to each of his seven children upon his death," Rowling said.
The Potter family history also reveals that Harry's strong moral character is actually a dominant ancestral trait. For centuries, the Potters fought to protect the Muggles, fighting against declaring war on the them and even campaigning to help them during the First World War. It was their outspoken support of Muggles that largely contributed to the Potter family's exclusion from the "Sacred Twenty-Eight," a list of the British families that were still "truly pure-blood" by the 1930s.
But by far the most intriguing tidbit Rowling revealed was the origin of Harry's invisibility cloak. It came into the Potter family when Linfred's eldest son, Hardwin, married a witch from Godric's Hollow, Iolanthe Peverell, the granddaughter of Ignotus Peverell of The Tale of the Three Brothers. "In the absence of male heirs, she, the eldest of her generation, had inherited her grandfather's invisibility cloak," Rowling wrote. "It was, Iolanthe explained to Hardwin, a tradition in her family that the possession of this cloak remained a secret, and her new husband respected her wishes. From this time on, the cloak was handed down to the eldest in each new generation."
In addition to the Potter family history, Pottermore also announced that it would now feature a Pottermore Correspondent, "a journalist dedicated to reporting on the latest updates going on in the Wizarding World." No details on who this correspondent will be, but long as it isn't Rita Skeeter, we'll be happy.