St Giles’ Cathedral, or the High Kirk of Edinburgh, is a parish church of the Church of Scotland located in the Old Town of Edinburgh. Likely founded in the 12th century and dedicated to Saint Giles, the church was elevated to collegiate status by Pope Paul II in 1467. In 1559, the church became Protestant with John Knox, the foremost figure of the Scottish Reformation, as its minister. After the Reformation, St Giles’ was internally partitioned to serve multiple congregations as well as secular purposes, including as a prison, and as meeting places for the Court of Session and the Parliament of Scotland. During periods of episcopacy within the Church of Scotland, St Giles’ briefly served as a cathedral in the 17th century. In 1637, a riot at St Giles’ against the religious reforms of Charles I precipitated the formation of the Covenanters and the beginnings of the Wars of the Three Kingdoms. In the 19th century, St Giles’ was restored and the internal partitions were removed. The current church building dates from the 14th century onwards and its distinctive crown steeple is one of Edinburgh’s best-known landmarks. Since the medieval period, St Giles’ has been the site of nationally important events and services and the chapel of the Order of the Thistle is located here. The church’s role in the Scottish Reformation and the Covenanters’ Rebellion has led to its being called "the Mother Church of World Presbyterianism". Alongside housing an active congregation, the church is one of Scotland’s most popular visitor sites, welcoming over a million visitors in 2018.

More details: https://en.wikipedia.org/wiki/St_Giles%27_Cathedral