Konstantinos Kapagiannidis was born in Trapezunta (today Trabzon) in 1868. His father was Gregory Kapagiannidis and his mother Domna Amiroglou. He graduated from the Trapezunta Tuition Center and was involved with his father’s merchant/trade business from a young age, a business which he helped to grow. He and his father then opened the Bank of Gregory Kapagiannidis, a bank which he and his youngest brother Alkiviadis co-managed. He was to work at the bank until his death. In 1904 he married Anna Triantafillidis and together they had 6 children, all boys. Around the start of the 20th century he built a villa at Soğuksu on the outskirts of Trapezunta, a villa which was named after him - the Kapagiannidis residence. Today it is a museum and is known as Ataturk's Kiosk because Mustafa Kemal Atuturk stayed there for 2 nights. He died in Trapezunta in 1915.
Above a sketch of the Kapagiannidis Bank in Trabzon, and senior staff of the bank with Alki Kapagiannidis seated in the center. Source
The Kapagiannidis residence at Soğuksu on the outskirts of Trabzon.