Short answers, pulled from the story.
The name Tamil appears in the earliest extant literary work known as the Tolkāppiyam, dated to the 2nd century BCE. Another early reference exists in the Hathigumpha inscription from around 150 BCE created by King Kharavela of Kalinga.
Scholars categorize the attested history into Old Tamil covering the era from 300 BCE to 700 CE, Middle Tamil running from 700 to 1600, and Modern Tamil beginning around 1600. Old Tamil is marked by short inscriptions in Tamil-Brahmi script while Middle Tamil features significant phonological shifts like the disappearance of the old phoneme aytam.
A corpus of 2,381 poems collectively known as Sangam literature survives from the Old Tamil period and is usually dated between the 1st century BCE and 5th century CE. These poems celebrate the Pandiyan Kings who organized long-term Tamil Sangams to research and develop the language.
Tamil became the first legally recognised Classical language of India following creation of legal status in October 2004. The recognition was announced by President Abdul Kalam in a joint sitting of both houses of Parliament on the 6th of June 2004.
The language had a listed vocabulary of over 470,000 unique words including those from old literary sources. Words like rice orange anaconda cheroot mango mulligatawny curry catamaran congee trace origins back to Tamil or Dravidian predecessors.