Some say it's Thomas and William Bowler, while some say it's Edward Coke, who was the younger brother of Thomas Coke, the First Earl of Leicester.

Each original purpose was one, for riding horses, or two, a durable hat.

Even the bowler hat was inspired by a previous creation named the Billycock hat.

Regardless of the beginning of the billycock hat, the first recorded creation of the bowler hat was in 1849. This hat was a chosen favorite because it was less likely to fall off, and it was fashionable. 

Sources:

https://www.historyofhats.net/hat-history/history-of-bowler-hat/

https://discover.hubpages.com/style/The-Bowler-Hat