Do you know the youngest double century maker in test history.?

On this day in 1976, one of the great batsman of cricket history, Javed Miandad scored a double century against New Zealanad at Karachi at the age of just 19 years. He started his test career on October 09,1976 against New Zealand at Kaddafi Stadium Lahore. He scored century in his first test and became the only second Pakistani after Khalid Ibadullah who scored century on his test debut. He was the youngest test century maker batsman (19 years and 119 days) for a long time but later on a Bangladeshi batsman Muhammad Ashraful scored a test century at age of 17 years. In the third match of  that series Javed Miandad scored a double century at Karachi at the age of 19 years and 141 days, and still he is the youngest test double century maker in test cricket history. Javed Miandad played 124 test matches for Pakistan and scored 8832 runs with the help of 24 centuries and the average of 53.74. His average never came down to under 50 in any stage of his entire career.