Question: DVDs on specific topics

I am currently looking (it's part of a project I am working on) for DVD (or even VCD) titles pertaining specific events and time periods of the history.

Specifically, I am interested into these:

- Seleucid empire, hellenistic world
- Macedonian phalanx
- Roman conquest under the Res Publica (punic wars included)
- Byzantium
- Medieval Knights
- Mongol Conquest
- Conquistadores and the American conquest

No films, please, anythinig else (documentaries, dramatized documentaries, documentary biopics, various features, reference stuff, whatever) is OK.

Please, any suggestions will be valuable.

Look for Michael woods documentaries on Alexander which is good but his Conquistadors one is fantastic. You can get them off Amazon i think