The Schmalkaldic League was organized in 1531 as a union of various Lutheran territories and cities, to provide a united military and political front against Roman Catholic politicians and armies, led by Emperor Charles V. Luther's patron, Elector John Frederick of Saxony, asked him to prepare these articles for League's meeting in 1537, held in Schmalkalden.
When the Schmalkaldic League met, Luther was taken very ill with a severe case of kidney stones and so was unable to attend the meeting.
Melanchthon was asked to write a clear statement on the papacy and this he did, a document that was adopted at the meeting as the Treatise on the Power and Primacy of the Pope.
Parts of Hesse accepted them as confessional writing in 1544 and in the 1550s, the Smalcald Articles were used authoritatively by many Gnesio-Lutherans as well as being incorporated into corpora doctrinae during the following 20 years.
All have sinned and are justified freely, without their own works and merits, by His grace (Eph 2:8-9), through the redemption that is in Christ Jesus, in His blood (Romans 3:23–28).