Lionel Kieseritzky, Estonian-French chess player (died 1853)

Lionel Adalbert Bagration Felix Kieseritzky was a Baltic German chess master and theoretician, known for his contributions to chess theory, as well for a game he lost against Adolf Anderssen, known as the "Immortal Game". Kieseritzky's name became associated with several openings and opening variations, such as the Kieseritzky Gambit, Kieseritzky Attack, and the Boden–Kieseritzky Gambit.

January 1 is the first day of the calendar year in the Gregorian Calendar; 364 days remain until the end of the year. This day is also known as New Year's Day since the day marks the beginning of the year.