the case of dead people, without knowing the traditional
pronunciation presumably, but not always, derived from that of the
person himself. (Welcome to the joys of English phonetics.)
If, as a native speaker of English, I were forced to read his
name out loud, I would pronounce it
OTT-red
but this may not be right.
My own grandmother, having remarried, in later life was Mrs.
Houghton; fellow Americans were constantly mispronouncing her name,
usually as Hoofton, Hewton, and Hoaton, all of which drove her
crazy. For the record, in her case it was Hawton: which does not
mean that other persons by the same last name might not pronounce it
some other way.
--
Bill Thayer
LacusCurtius
http://www.ukans.edu/history/index/europe/ancient_rome/E/Roman