The Idumeans and their Pahlavi Hagarim made a treaty with the house of Sassan in 632. The house of Sassan were allowed to place Yazdegard III on a throne controlled by Idumeans and their Pahlavi Hagarim.
However, Karaite Jews conquered the Idumeans in 633 so the Sassanians and the Pahlavis defended themselves but were suppressed in 636 by Umar who got the Idumeans on his side by arranging a marriage between a princess from the House of Sassan and a prince from the Idumean house of Ali to rule after Yazdegard III which they eventually did when Yazdegard III died in 651. However, a civil war broke out in 565 which caused Muawiya to secede Damascus away from the Idumean confederation.
Muawiya eventually made a treaty with the Idumean confederation again in exchange for rule until his death in 680 but then his son Yazid killed the Alid Prince and broke away again which allowed ibn Al-Zubayr to take control of the Idumean confederation.
The Idumeans were forced to accept the Anno Hegira as they began to be conquered one by one by Abdul Malik from 692AD.