Colasterion (from the Greek word for "instrument of punishment"[1] or "house of correction"[2]) was published by John Milton with his Tetrachordon on 4 March 1645.
Milton married in Spring 1642, and shortly after, his wife Marie Powell, left him and returned to live with her mother.
[3] The first tract was created during a time of humiliation, and Milton was motivated towards writing on the topic after reading the work of Martin Bucer on divorce.
[5] This reconciliation could have come in part from the failure of the royalists, including Powell's family, to prevail during the English Civil War and lacking justification to further distance themselves from Milton.
[6] According to George Thomason, an early collector of English Civil War tracts, Colasterion was published on 4 March 1645 along with Tetrachordon.