The British soldier killed in Afghanistan on Friday has been named as Private Chris Gray, of the 1st Battalion Royal Anglian regiment.
Pte Gray was proud to serve his country, his family said
The 19-year-old from Leicester was on a routine patrol in Helmand province when he came under small arms fire.
The Ministry of Defence said it took place after troops challenged a Taleban team trying to set up an ambush.
Lt Col Stuart Carver said Pte Gray had died "selflessly striving to relieve comrades in extreme danger".
Pte Gray joined the British Army just over a year ago, and had been based near the town of Now Zad, in north-west Helmand province, southern Afghanistan.
The MoD said a number of soldiers were in a "fierce firefight" at a range of just 15 metres, in which a small number of Taleban were killed and Pte Gray was shot.
He was airlifted to the main British base at Camp Bastion, but was pronounced dead on arrival.
His company commander, Major Dom Biddick MBE, said Pte Gray was passionate about his job and showed leadership potential.
"Grayman, as he was known to his friends, was a young man with a big heart and a calm, generous and immensely trustworthy personality."
His friend, Private Matt Duffy, also in the regiment known as the Vikings, described his as "an awesome soldier and a better mate".
"He loved the job more than anyone and died doing what he loved."
In a statement, Pte Gray's family said: "He was a much loved and cherished son, grandson and brother, who was proud to serve his country. He will always be missed."
Defence Secretary Des Browne said his thoughts were with Pte Gray's family.
His death took the number of UK troops killed in operations in Afghanistan since 2001 to 53.