Saadat Lineage
They actually come from three daughters of the prophet: Fatima, Ruqayya, and Zainab. However, the descendants of Fatima are usually named Sadaat. This is all because the descendants of Fatima got involved in politics after her Husban Hazrat Ali, as opposed to others and some of them became prominent in the world of academics. So they became the focus of attention of the people and the others were almost completely forgotten. Some scholars have written some books on the descendants of other daughters too.