欧阳Ōuyáng
A two-character surname: keep both characters together when identifying the given name.
A historical connection
Ouyang Xiu was a Song writer and official. His name is a clear historical example of the compound surname.
The named reference here is Ouyang Xiu. It gives a point of entry into history; it cannot establish the origin or genealogy of everyone who writes this surname.
A compound surname seen in an actual historical name
The Palace Museum records Ouyang Xiu as a Northern Song writer and official, and also gives his courtesy name and later literary names. In 欧阳修, 欧阳 is the two-character surname and 修 is the personal given name. His other names belong to historical literary practice; they are not extra characters in the surname.
Why this matters when choosing a name
A learner reading 欧阳瑾言 must keep 欧阳 together before interpreting 瑾言. Counting the first character as the entire surname would corrupt every subsequent explanation, including the pinyin boundary and the given-name meaning.
What this evidence cannot say: Ouyang Xiu shows that the compound surname was borne by a documented individual. His biography does not make every modern 欧阳 a descendant, nor does it imply that a learner needs a courtesy or art name.
What to check in your own name
Say the whole name aloud, including its surname/given-name boundary. Check the surname’s tone and whether the next syllable begins comfortably. If your family already uses a Chinese surname, use its own documented written form and reading instead of replacing it with an attractive historical story.
These combinations are exploration examples. Only the linked dossier’s original surname pairing has its specific editorial note; a changed surname needs fluent-speaker review.
Sources & limits
Sources support the specific facts cited above. An editorial name interpretation is not an ancient quotation or proof of family ancestry.