And listen to the Hallelujah chorus from Messiah. At long last, after much frustration, I have solved the problem of too few episodes of British History 101 showing up in iTunes; until now, listeners could only go back about as far as Queen Elizabeth II. However, I have consulted with both iTunes and my hosting service and found that…
…the problem was my fault all along.
Yes, indeed, I caused all the consternation myself. There is a simple setting in my hosting account which is labeled “Number of episodes to display.” I had this setting (which I have never seen before) set to 25, which explains why all the podcasts weren’t up. After changing in to “All” and allowing iTunes to cycle through, I see that each and every episode of British History 101 is now available! Thank you, Hipcast technical support!
British History 101 
Woo hoo – looking forward to going back to the start now!