The name "Octavian"

[hansvl]

I think we're at crossed purposes here, David. Names in -anus or -ienus usually do not imply adoption. There are many perfectly normal names of that form -- Jona posted a list earlier. But it seems to have been assumed that, if a person happened to be adopted, he would convert his existing name so that it ended -ianus. Jona has drawn our attention to the fact that, apart from the well-known and often-quoted Scipio Aemilianus, we struggle to find other examples. As I noted above, adoption was normally advertised through other means.

What about the case of Lucius Aelius Seianus, the notorious praefectus praetorio of emperor Tiberius. His father's name was Lucius Seius Strabo and ruled with his son as his collegue praefectus praetorio for a while. Seianus was adopted into the gens Aelia by Aelius Gallus.
So, is this not an exemple of a name on -ianus from an adoption?

Hans