From Living for God’s Glory by Joel Beeke:
The confession of faith produced by the Westminster divines has undoubtedly been one of the most influential documents of the post-Reformation period of the Christian church. A carefully worded exposition of seventeenth-century Reformed theology, the calmness of its sentences largely hides the tempestuousness of the political backdrop against which it was written.
The Westminster Assembly was convened in 1643 after years of tension between England’s King Charles 1 and his increasingly Puritan Parliament. Meeting under the chairmanship of the learned William Twisse against the king’s express wishes, its vision was to effect closer uniformity of faith and practice throughout Charles’ realm. The original task of the mostly Puritan delegates was to revise the Thirty-Nine Articles of the Church of England, but following the signing of the Solemn League and Covenant between Parliament and the Scottish Covenanters in 1643, this developed into the more specific and exacting task of framing theological and ecclesiastical formulas that would bring the Church of England into conformity with the doctrine and practice of the Presbyterian Church of Scotland. …
For all practical purposes, [the] Scottish delegates constituted the most powerful group among those who gathered in the Chapel of Henry VII and later in the Jerusalem Chamber at Westminster Abbey, London, during the years of discussion and debate. While the majority of the delegates seem to have been of Presbyterian persuasion to varying degrees, Episcopalians and Independents were also represented, the latter group … at times exasperating the Scots.
…Despite disagreements, the divines produced on of the truly monumental documents of church history, which has instructed, directed, and profoundly influenced Presbyterian churches worldwide ever since.