While he has been called the "Merry Monarch" his reign was far from untroubled. In 1665 a terrible plague struck England, and the following year saw the Great Fire of London. What caused tension throughout his reign was his sympathy for Catholicism, inherited from his father and undoubtedly strengthened during his French exile.
In 1670 Charles entered into the Secret Treaty of Dover, in which he pledged to support France in its war against the Dutch Republic and to convert to Catholicism at an unspecified time (he did so, on his deathbed). This led to the Third Anglo-Dutch War, concluded in 1674 by the Treaty of Westminster, under which, among other things, the Dutch returned their colony of New Netherland to the English, who renamed it New York.
Catherine of Braganza (portrait by Peter Lely, public domain, via Wikimedia Commons). She was a Portuguese infanta, or princess, whose marriage to Charles at the age of 21 was, like almost all European royal marriages, diplomatically arranged. Her dowry included Bombay, now Mumbai, thereby helping to establish the British foothold in India. The marriage didn't get off to a good start. She developed a nosebleed and fainted when told that Charles had made his favorite mistress, Barbara Palmer, her Lady of the Bedchamber, or personal attendant.
Despite this and many other discourtesies, Catherine remained faithful to Charles until his death. To his credit, Charles resisted entreaties to divorce her when she suffered three miscarriages and failed to produce a legitimate heir to the throne. After Charles died she remained in England through the short, unhappy reign of her brother in law, James II, and the "Glorious Revolution" of 1688, which sent James into French exile and gave the crown to his daughter, Mary, and her husband, William of Orange, whose marriage had been arranged by Charles to placate Protestants and secure realtions with the Dutch. Under William and Mary, Protestant power was solidified by Parliament, which passed an "Exclusionary Act" barring Catholics from the throne. Catherine returned to Portugal in 1692, where she spent her later years active in affairs of state, serving on two occasions as regent for her brother, Peter II, and helping to secure a treaty between Portugal and England. She died in 1705 and is buried at the monastery of São Vicente de Fora.
As a Brooklynite I hate to say this, but, Queens, you got the better of the two royals.