King George I of England
Because Queen Anne had no children, and no Catholic could be king or queen, when she died in 1717 AD her cousin George - James I's great-grandson - became King George I of England. George was born in Germany and grew up speaking German and ruling part of Germany, so it seemed funny to have him become King of England when he was already 54 years old. Parliament took over more and more power instead, and soon the Prime Minister, Robert Walpole, made most of the decisions. Under Walpole, England's navy got stronger and stronger - stronger than Spain's navy, or any other navy in the world.
George's son George II ruled after him, starting in 1727, but Walpole continued to hold the real power. Walpole sent settlers to conquer land in North America south of the Carolinas. They named their new land Georgia after the king. There was more fighting over who would control Spain. Walpole lost power in 1742, and first Carteret and then Pitt ended up controlling Parliament.
Then in 1760 George II's grandson ruled as George III. This is the George who was king when Thomas Jefferson wrote the Declaration of Independence. But even though Jefferson addressed the Declaration to the King, really it was the Prime Minister who was making the decisions. In the 1780s, the Prime Minister William Pitt organized cotton-growing in British colonies in Africa, in order to compete with United States and Indian cotton and keep the British spinning and weaving factories supplied with plenty of cotton. In 1793, Pitt joined Austria, Prussia, and Spain in fighting against the French Revolution. By 1796, this put them all at war with Napoleon.
George III's son George IV took over in 1810, because George III was suffering from mental illness and couldn't rule. So it was George IV's prime minister who ran the War of 1812, and who defeated Napoleon at Waterloo. George IV died without sons so his younger brother William became king.