William IV was King of the United Kingdom of Great Britain and Ireland from 26 June 1830 until his death in 1837. The third son of George III, William succeeded his elder brother George IV, becoming the last king and penultimate monarch of Britain's House of Hanover.

William served in the Royal Navy in his youth and was nicknamed the "Sailor King". In 1789, he was created Duke of Clarence and St Andrews. In 1827, he was appointed as Britain's first Lord High Admiral since 1709. As his two older brothers died without leaving legitimate issue, he inherited the throne when he was 64 years old. His reign saw several reforms: the poor law was updated, child labour restricted, slavery abolished in nearly all of the British Empire, and the British electoral system refashioned by the Reform Act 1832. He was the last monarch to appoint a prime minister contrary to the will of Parliament.

At the time of his death William had no surviving legitimate children. He was succeeded by his niece Victoria and in Hanover by his brother Ernest Augustus.

Charles Grey, 2nd Earl Grey, (13 March 1764 – 17 July 1845), known as Viscount Howick between 1806 and 1807, was a member of the Whig Party and was a long-time leader of multiple reform movements, most famously the Reform Act 1832. His government also saw the abolition of slavery in the British Empire, in which the government purchased slaves from their owners in 1833. Grey was a strong opponent of the foreign and domestic policies of William Pitt the Younger in the 1790s. In 1807, he resigned as foreign secretary to protest the King's uncompromising rejection of Catholic Emancipation. Grey finally resigned in 1834 over disagreements in his cabinet regarding Ireland, and retired from politics.

Earl Grey tea is named after him.

James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics. His most notable achievement was to formulate the classical theory of electromagnetic radiation, bringing together for the first time electricity, magnetism, and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the "second great unification in physics" after the first one realised by Isaac Newton.

His discoveries helped usher in the era of modern physics, laying the foundation for such fields as special relativity and quantum mechanics. Many physicists regard Maxwell as the 19th C scientist having the greatest influence on 20th C physics. On the centenary of Maxwell's birthday, Einstein described Maxwell's work as the "most profound and the most fruitful that physics has experienced since the time of Newton".