The British Mrs. O'Leary: Thomas Farynor, royal baker to King Charles II of England
His "Cow": His oven, which sparked a fire in the middle of the night on September 1, 1666.
Oops: Around 2 a.m., smoke woke up the Farynor family and their servants in the house above the bakery. Luckily, the entire lot managed to escape—all except for one maid who was too frightened to run and became the fire's first victim. The blaze quickly spread, but surprisingly, the conflagration alarmed almost nobody. People from around the neighborhood crawled out of bed to watch it and, when the mayor of London was brought by later that morning, he declared it small enough that "a woman might piss it out." Yes, that's a direct quote. But by mid-afternoon, the time to extinguish the fire in said manner had passed. Fed by a dry wind and London's seemingly inexhaustible supply of flammable objects, it burned for five days, wiping out some 13,000 homes and razing 80 percent of the city.
Even after the main blaze died down, small fires remained for months afterwards.
But It Wasn't So Bad, Really: For one thing, the hapless Farynors were never held responsible for the fire. In the immediate aftermath, most average Londoners were more interested in blaming Catholic extremists from France. Meanwhile, government authorities were so busy saving random foreigners from impromptu lynch mobs that they had no time to worry about the royal baker. Amazingly, the Great Fire of 1666 (as it became known) did bring about some good—it killed off most of London's rat and flea populations, thus bringing an end to the Great Plague of 1665.