By Grace of God Protector of the Commonwealth

In OTL, the Parliamentarians won the English Civil War. This led to massive upheavals in the government that hadn't been seen before to this degree with the Monarchy being banished from the realm. But afterwards Oliver Cromwell became the Lord Protector, itself much like the monarchy. After Oliver Cromwell died in 1658 his son Richard Cromwell took over as Lord Protector. Though he failed in this position and led to Charles II being appointed King of England and Scotland again. The POD in this scenario is that many influential Parliamentarians such as John Lambert were more republican rather than wishing to keep a monarchy. Another POD is that Charles Fleetwood, husband of Oliver Cromwell's daughter, actually took over as Lord Protector rather than the inexperienced Richard Cromwell.