It erupted between 1821 and 1823 and when it ceased 1823 it triggered a bigger volcano- the Katla- which erupted in 1823.
I enjoyed my train ride to London- you meet so many people with different stories. My US colleagues couldn't make it here. One US lady who came over for a vacation with her family on my recommendation (they were at the place Edwina's Secretary and I were 4 years ago) couldn't go back. One UK colleague is in Mexico with his family, another German colleague is stuck in Hong Kong and they say they cannot get him back before 1st of May.
2 South African ladies I met in the hotel are stranded since wednesday last week. The bad thing is you have to check your airline all the time, are on the phone no end or are trying to access overloaded servers. I have already booked a train ticket back home on Friday but still hope I can make it flying- stay tuned