Online math history lectures This question is somewhat similar to this: Best online mathematics videos?
I'm using the word "history" loosely here. What I'm looking for are those lectures that put various mathematical developments in perspective by explaining their origins. There's something very insightful about seeing someone talk about the origins of a concept, that makes things click. Especially if he or she partook in the inception of that development.
So: where can I find such lectures online?
 A: You may wish to look at the plenary lectures of the 2009 annual meeting of the Australian Mathematical Society (especially the two Tao's lectures)
http://www.unisa.edu.au/austms2009/videos/default.asp
and at the plenary talks at ICM 2010: 
http://www.icm2010.com/archievedvideos.asp
(the commented listing of the videos can be found at this post of Timothy Gowers' blog)
Also, there is an extensive collection of the MSRI videos
http://www.msri.org/communications/vmath/index_html
of which I list here just a few examples that hopefully should meet your requirements regarding the discussion of historical aspects:
Roger Penrose: Twistor Theory, Old and New 
Lectures on the Fermat's Last theorem
Irving Kaplansky's 80th Birthday Celebration
Last but not least, there is a large searchable collection of videos (mostly in Russian) at
http://www.mathnet.ru/php/presentation.phtml?option_lang=eng
where you can find e.g. 
L.D. Faddeev's talk on the history of quantum groups (in Russian)
Yu.I. Manin's talk on the history of Euler products (in English)
A.M. Vershik's talk on the history and perspectives of the Kolmogorov entropy (in Russian)
A: There are some videos relevant to the history of mathematics at the Clay Mathematics Institute (http://www.claymath.org/video/) and at the Fields Institute http://www.fields.utoronto.ca/audio/
The Fields section is titled "Audio and Slides" but there are some videos too.
Cheers, Scott
A: I just came across these BBC podcasts the other day.  These are almost certainly more populist than you had in mind, but given the title of your question I thought I would throw it up here anyway.  The are ten podcasts.  Some expire in a day or so, which made me think posting it for those interested was a decent idea.


*

*Newton and Leibniz

*Leonard Euler

*Joseph Fourier

*Evariste Galois

*Carl Friedrich Gauss 

*The Mathematicians Who Helped Einstein

*Georg Cantor 

*Henri Poincare 

*Hardy and Ramanujan 
10.Nicolas Bourbaki


http://www.bbc.co.uk/programmes/b00srz5b

"Professor of Mathematics Marcus du
  Sautoy reveals the personalities
  behind the calculations and argues
  that mathematics is the driving force
  behind modern science"

