Question

During the reign of which English king was there a succession crisis between his supporters and those of his cousin, the Empress Matilda?

Answer 1

Stephen
The period of Stephen's reign (1135–1154) was known as "The Anarchy" or "The Nineteen-Year Winter". The succession issue was resolved shortly before Stephen's death, when he signed the Treaty of Wallingford, which named Matilda's son Henry Curtmantle as his heir. Henry was crowned upon Stephen's death.