Former teachers have remembered Aqeel Khan, who was fatally stabbed in West Watford last week, as a "polite, courteous and respectful young man".
The principal of West Herts College, which the 18-year-old attended last year, said the thoughts of staff and students were with his family.
Aqeel was found collapsed in Croxley View on Friday afternoon. He was rushed to Watford General Hospital but died shortly after.
A 16-year-old boy has since been charged with murder and a 15-year-old boy with affray in connection with the case.
West Herts College principal, Gill Worgan, said: "The loss of any life is always tragic, even more so when it happens at such a young age.
"The thoughts of everyone at the college are with Aqeel’s family and friends at this difficult time.
"Aqeel completed a course with us last summer and the staff who knew him best describe him as a polite, courteous and respectful young man."