Ashura - Details of the annual observance by Muslims on the tenth day of Muharram.
Wikipedia: Aashurah - Commemorates the death of Husayn bin Ali, the grandson of Muhammad and the third Imam of the Shi'as, at the Battle of Karbala in the year 61 AH.
BBC: Ashura - Islamic observance celebrating the day Prophet Nuh left the ark and the day Prophet Musa was saved from the Egyptians by Allah.
Probe Into The History of Ashura, A - Online rendition of the book by Dr. Ibrahim Ayati exploring the sacrifice made by Imam Husayn on the 10th of Muharram in 61 A.H.