Many cultures have a Thermopylae. For the Muslims, it was the battle of Uhud on 23 March 625. When the Muslim line broke and their retreat turned to rout, it was Nusaybah, her two sons and husband who helped form the ring of ten that protected the Prophet (ASWS). It was on that day that the Prophet (ASWS) prayed that Nusaybah and her issue be his companions in Heaven.
She was one of those who pledged to die with the Prophet (ASWS) at the pledge of al-Radwan.
In the battle of Hunayn in 629, the Muslims again broke and Nusaybah's sons yet again stood fast by the Prophet (ASWS).
Later after the Prophet's death (ASWS) Habib ibn Nusaybah was captured by Musaylama the pretender. Musaylama asked him to betray Islam by declaring that Musaylama was God's prophet, and tortured him cutting off his organs one by one to force him to do so. Habib's only reply was "I cannot hear you".
It was Habib's brother Abdullah who killed Musaylama in the ensuing battle, in which Nusaybah also fought.