If my grandfather's name was changed by immigration, how can I find out what it was?
My grandfather was born in Greece, 1/6/1901. His parents immigrated first to Canada, then New York when he was about 13. I would like to get a copy of his birth certificate so that I can apply for Greek citizenship, but I was told that his father's surname was changed at immigration. His mother's maiden name was Constantina Anavrides. His father's first name was Demetrius. I do not have a copy of their marriage certificate and I was only told they came from Sparta. George Chahalis died in April, 1983, in Riverhead, NY. My Mother is half Greek, half Irish. Do I have to have certified documents to apply for dual citizenship with USA and Greece?