They’re very popular. I missed one this month as I was too late trying to register. Here’s the programme for September for which registration is scheduled to open today.
Friday, 3 September, 9 am EDT: Recovery from the Black Death in late-medieval Britain and Ireland, by Paul Dryburgh, TNA Principal Records Specialist (Medieval Records).
Wednesday, 8 September, 2:30 pm EDT: Writing John of Gaunt, The Red Prince: a conversation with Helen Carr.
Friday, 10 September, 9 am EDT: Recovery and Regeneration after the Great Fire of London (1666), by TNA Early Modern Record Specialist Philippa Hellawell.
Tuesday, 14 September, 9 am EDT: Top Level Tips: Wills and other Probate Records before 1858, by Ruth Selman, TNA Principal Early Modern Records Specialist.
I love these lectures. There are some good ones from Gresham College & York University (UK) as well.