urkundlich
documented
Proven or verified by a certificate, deed, or another official written document.
Die erste urkundliche Erwähnung des Dorfes stammt aus dem Jahr 1254.
The first documented mention of the village dates from the year 1254.

documented
Loading your saved state.
documented
Proven or verified by a certificate, deed, or another official written document.
Die erste urkundliche Erwähnung des Dorfes stammt aus dem Jahr 1254.
The first documented mention of the village dates from the year 1254.

The adjective 'urkundlich' (documented/by document) is derived directly from the noun 'die Urkunde' (certificate/deed). An 'Urkunde' is an official, often old document that proves a fact.
Im Stadtarchiv wird die Gründungsurkunde der Stadt aufbewahrt.
The city's founding charter is kept in the municipal archive.
By far the most common combination is 'urkundlich erwähnt' (documented in writing/mentioned in a document). This expression is used to describe the first written evidence of the existence of a place or person in history.
Die Burg wurde im 11. Jahrhundert erstmals urkundlich erwähnt.
The castle was first documented in the 11th century.
'Urkundlich' (by document/documented) is almost always used as an adverb that defines a verb more precisely. It answers the question 'How is it documented?'. Typical verbs are 'erwähnen' (to mention), 'belegen' (to document/prove), or 'nachweisen' (to verify/prove).
Es ist urkundlich belegt, dass die Brücke schon im Mittelalter existierte.
It is documented that the bridge already existed in the Middle Ages.
This word belongs to the language of historians, lawyers, and administration. It is often found in texts about history, in archives, or in official documents.
Der Historiker sucht nach einer urkundlichen Bestätigung seiner These.
The historian is looking for documentary confirmation of his thesis.
written
'schriftlich' and 'urkundlich' both have to do with written form. 'Schriftlich' is the normal word when something is written, for example in a letter, form, or email. 'Urkundlich' is narrower and more official: something is proven by a certificate, deed, or official document. The words can be confused because a document is also written. But not everything written is 'urkundlich'. For normal messages, applications, or confirmations, 'schriftlich' fits. For official proof, 'urkundlich' fits.

Der Besitz des Hauses ist urkundlich nachgewiesen.
Ownership of the house is documented by official records.
Bitte bestätigen Sie den Termin schriftlich per E-Mail.
Please confirm the appointment in writing by email.