Cook was included in the ECB National Academy in the winter of 2005–06.
The Academy's tour of the West Indies was cut short on 24 February for Cook who only appeared in the first innings, scoring only 6, before being called up, alongside James Anderson and Owais Shah, to the England tour of India to replace captain Michael Vaughan, who was suffering from a knee injury, and opener Marcus Trescothick, who was suffering from stress.
Unlike Shah and Anderson, Cook was welcomed straight into the England XI and made his Test debut aged 21, days after he had flown in from the West Indies.
He made an instant impact, opening with Andrew Strauss and scoring a half century in the first innings before being bowled just before tea on the first day for 60 runs from 160 balls being the second top scorer after 134 from Paul Collingwood.
The second innings would prove to cement him in cricket history as he went on to score 104 not out before England declared, making him the sixteenth Englishman to score a century on his debut Test and an even more exclusive list of five to score 100 and 50 in their first Test.
His hundred was also the 3,000th century in Test cricket.
Despite being known for a patient style of play, an impending declaration forced Cook to play quickly to bring up the century; regardless, the match was drawn.
After a mediocre outing in the losing second Test, scoring 17 and 2, he missed the Third Test due to a stomach illness and was omitted from the one-day series.

Returning home, Cook was again selected for the first XI during Sri Lanka's tour.
For his debut match at Lord's, Cook was shuffled down to third to make way for the returning Trescothick.
However, he still walked to the crease alongside his teammate as Strauss fell at the stroke of lunch.
Cook and Trescothick put on 127 in their partnership as Trescothick made a century while Cook later stumbled just before at 89; there was no second innings as England enforced the follow-on but were one wicket away from victory, with Cook being targeted among others for two significant dropped catches.
Cook's first taste of victory came in the second Test, guiding the team past the target of 78 in the second innings with an unbeaten 34 alongside Andrew Flintoff furthering the reputation of his calm, meticulous style of play against the dangerous spin of Muttiah Muralitharan who took 4–29.
Although not initially selected for the one-day series, Cook made his limited overs debut in the fourth match scoring 39 from 38 balls in a bright spot of an otherwise dour England performance hampered by injuries.
Cook was included in the ECB National Academy in the winter of 2005–06. The Academy's tour of the West Indies was cut short on 24 February for Cook who only appeared in the first innings, scoring only 6, before being called up, alongside James Anderson and Owais Shah, to the England tour of India to replace captain Michael Vaughan, who was suffering from a knee injury, and opener Marcus Trescothick, who was suffering from stress. Unlike Shah and Anderson, Cook was welcomed straight into the England XI and made his Test debut aged 21, days after he had flown in from the West Indies. He made an instant impact, opening with Andrew Strauss and scoring a half century in the first innings before being bowled just before tea on the first day for 60 runs from 160 balls being the second top scorer after 134 from Paul Collingwood. The second innings would prove to cement him in cricket history as he went on to score 104 not out before England declared, making him the sixteenth Englishman to score a century on his debut Test and an even more exclusive list of five to score 100 and 50 in their first Test. His hundred was also the 3,000th century in Test cricket. Despite being known for a patient style of play, an impending declaration forced Cook to play quickly to bring up the century; regardless, the match was drawn. After a mediocre outing in the losing second Test, scoring 17 and 2, he missed the Third Test due to a stomach illness and was omitted from the one-day series.
Returning home, Cook was again selected for the first XI during Sri Lanka's tour. For his debut match at Lord's, Cook was shuffled down to third to make way for the returning Trescothick. However, he still walked to the crease alongside his teammate as Strauss fell at the stroke of lunch. Cook and Trescothick put on 127 in their partnership as Trescothick made a century while Cook later stumbled just before at 89; there was no second innings as England enforced the follow-on but were one wicket away from victory, with Cook being targeted among others for two significant dropped catches. Cook's first taste of victory came in the second Test, guiding the team past the target of 78 in the second innings with an unbeaten 34 alongside Andrew Flintoff furthering the reputation of his calm, meticulous style of play against the dangerous spin of Muttiah Muralitharan who took 4–29. Although not initially selected for the one-day series, Cook made his limited overs debut in the fourth match scoring 39 from 38 balls in a bright spot of an otherwise dour England performance hampered by injuries.
Alastair Cook