Katalin

This spelling form is Hungarian. Imagine that many centuries ago the Greek name Aikatarina went to Katerina and Catherine in many countries/regions. But in some places Catherine got variations like Cateline in France and Catalina in Spain (Kattalin in Euskal Herria, Basque country, that's right) and Caithlin in Ireland which might be the variation of Catherine all English speaking people are most familiar with. Well in Hungary it became Katalin and it is a very popular name there, in all generations.