I first read the Lord Tedric series about 10 years ago (1999). This series of books is based upon Smith's novelette entitled "Lord Tedric" orginally published in Other Worlds in 1952.
It was not until, approximately 13 years, after Smith's death, that Gordon Eklund published another novel of the same name about the same character, introducing it as "a new series conceived by E. E. 'Doc' Smith". Eklund later went on to publish the other novels in the series under the pseudonym "E. E. 'Doc' Smith".
The four books in the seres are:
1. Lord Tedric
2. The Space Pirates
3. Black Knight of the Iron Sphere
4. Alien Realms
Of the four books in the series, I have have read (December 2009) the first three. I have yet to locate and obtain a copy of "Alien Realms" but have hopes of finding one in the near future. When I do obtain a copy of "Alien Realms" it will be a first time read for me.