A university cleaner has graduated with a degree in classics after combining his work duties with a study programme for 14 years.
Gac Filipaj, 52, was feted by fellow students and dons at Columbia University as he received the award 20 years after he fled war-torn Yugoslavia.
When he arrived in New York in 1992 he could not speak English and spent the next five years learning the language.
His role as a cleaner at the prestigious Ivy League university meant he qualified for free study hours and was able to work on getting a degree.
"This is the proudest moment of my life," he told colleagues as he graduated.
"The way I was educated in my family was to not seek fortune or fame, but to live a simple, honest and honourable life.
"I asked people 'which are the best schools in New York?' So I went to Columbia to see if I could get a job."
University bosses paid tribute to his hard graft and spirit, hailing his achievement as "one of the great stories here".
"He didn't just study alongside Columbia University students, he competed with them," said Professor Peter J Awn.
"He is immensely humble and grateful, but he's one individual who makes his own future.
"This is a man with great pride, whether he is doing custodial work or academic work."
Mr Filipaj's graduation comes after years of completing 10-hour shifts as late as 11pm and only then opening the books to begin his academic work.
He still sends part of his \$22-per-hour pay back to his brother and family in Montenegro.
"The richness is in me, in my heart and in my head, not in my pocket," he told reporters.
He now intends to step up his academic work with a view to getting a Masters degree.