Who invented the Twix candy bar?

The Twix candy bar was invented by Forrest Mars Sr. The candy bar, consisting of twin sticks of shortbread individually topped with caramel and covered with chocolate, was made and sold in the United Kingdom by Mars Limited in 1967.

Forrest Mars Sr. was the son of the American entrepreneur Frank C. Mars, who first began making and selling candies under the Mars name from his kitchen in Tacoma, Washington. Forrest joined his father's business but ventured to the U.K. to expand its market. He set up Mars Limited and subsequently created the Twix bar. Despite its popularity in the U.K. the candy bar did not actually retail in the United States until the debut of the Twix Caramel Cookie Bar in 1979.