Who invented the modern crossword puzzle?

Arthur Wynne (June 22, 1871 – January 14, 1945) was the British-born inventor of the modern crossword puzzle.

A crossword is a word puzzle that usually takes the form of a square or a rectangular grid of white- and black-shaded squares. The game's goal is to fill the white squares with letters, forming words or phrases, by solving clues, which lead to the answers. In languages that are written left-to-right, the answer words and phrases are placed in the grid from left to right and from top to bottom. The shaded squares are used to separate the words or phrases.

Wynne created the page of puzzles for the "Fun" section of the Sunday edition of the New York World. For the December 21, 1913, edition, he introduced a puzzle with a diamond shape and a hollow center, the letters F-U-N already being filled in. He called it a "Word-Cross Puzzle."