Ducay

The same name, spelt two ways

One systematic substitution — s for z, w for v, ch for h — where BOTH spellings are independently attested surnames. Kosina and Kozina are one man in two clerks' handwriting. Stronger than sounding alike, weaker than somebody having checked.

Ducai

Where it came from

No place of this name is in the gazetteer, so this map says nothing about where the name came from. Search a surname anywhere else and you will be told an origin — that it is Latin, or Italian, or means «joyful». That is etymology, it is usually unsourced, and it is a different question from the one answered here.

Where it is borne, and where a record names it

Country by country

Each country below can carry up to three different kinds of evidence, and none of them is the same claim. A register is a head-count — a state counted these people. A record is one document naming the surname on that ground, narrower evidence and often much older. And a volume overlapping these dates is a document from the right place and years — never a document known to name this surname. None of the three ever means the name exists in that country and nowhere else, or that it exists nowhere but here.

When it was being born, in France

INSEE counts births by surname and decade from the état civil, 1891 to 2000 — the only dated evidence in this dataset. A name that starts at zero and climbs arrived; a name that falls to nothing left, died out, or emigrated, and the decade it stops is the decade to stop searching. It counts births registered in France, so a family that emigrated in 1900 simply stops appearing, which is information rather than a defect.

• 1891–1900 12
• 1901–1910 25
• 1911–1920 18
• 1921–1930 24
• 1931–1940 10
• 1941–1950 18
• 1951–1960 24
• 1961–1970 17
• 1971–1980 17
• 1981–1990 17
• 1991–2000 18

Whose archive held that ground, and when

Every surname site can tell you a name is common somewhere. This one also knows which filing system held that ground in which years — and those are the two halves of one question: my people were called this, they were there, so who has the paper, and for which century. A name in Croatia before 1881 may sit in a military series and not a county one; a name in the Netherlands before 1811 has no civil record at all, only a baptism.

This is about the ground, not about your family. A register counting a name in a country says nothing about which village. And these are the pieces of a country this atlas has drawn, which in a large one may be a corner of it — Acadia reaches into Maine and is not a statement about the United States, and Bohemia's ground crosses into Poland. Each region's own page says which ground it covers. Where a country is missing below, nothing covers it yet.

No record region is drawn yet for Spain — which is a gap in this atlas and not a statement about that country.