Short answers, pulled from the story.
The historical figure behind Santa Claus was a Greek Christian bishop named Nicholas who lived in Myra during the 4th century. He became famous for his generosity toward the poor and remains the patron saint of children today.
Merchants from Bari removed major bones from Saint Nicholas's sarcophagus in 1087 when Muslim Seljuq dynasty forces had subjugated the area. These sailors took the relics to Bari against the wishes of local monks where they are enshrined in the Basilica di San Nicola.
An anonymous poem titled A Visit from St. Nicholas appeared in the Troy New York Sentinel on the 23rd of December 1823. Clement Clarke Moore later claimed authorship while others argued Henry Livingston Jr wrote it before dying nine years prior to Moore's revelation.
The Guinness World Record for largest gathering of Santa Clauses occurred in Thrissur Kerala India on the 27th of December 2014 when 18,112 Santas participated. Another record attempt happened in Derry City Northern Ireland on the 9th of September 2007 when 12,965 people dressed up as Santa or helpers.
NORAD Tracks Santa originated in 1955 when a Sears-Roebuck ad incorrectly printed their hotline number leading Continental Air Defense Command to receive calls intended for Santa. The program transferred to NORAD when it was jointly founded by the United States and Canada in 1958.