This included as Viceroy in famine-stricken Ireland and, on the first of three occasions as Foreign Secretary, as the United Kingdom's chief representative at the Congress of Paris which ended the Crimean War.

[1] Villiers was educated at Christ's Hospital and St John's College, Cambridge, which he entered at the early age of sixteen, on 29 June 1816.

The Encyclopaedia Britannica stated that he had "received from nature a singularly handsome person, a polished and engaging address, a ready command of languages, and a remarkable power of composition".

He was unjustly accused of having supported the revolution of La Granja, which drove Christina, the Queen Mother, out of the kingdom, and raised Espartero to the regency.

He reluctantly supported Foreign Secretary Lord Palmerston's expulsion of the pro-French Mohammed Ali of Egypt from Syria but did not resign as it might break up a cabinet he had so recently joined.

[3] During Sir Robert Peel's Conservative administration (1841–1846) Lord Clarendon took a strong interest in the triumph of free trade and in the repeal of the Corn Laws, a policy of which his younger brother Charles Pelham Villiers had been one of the earliest champions.

[5] Despairing of effective famine relief, Clarendon suggested to Russell, that "there is not another legislature in Europe that would disregard such suffering as now exists in the west of Ireland, or coldly persist in a policy of extermination".

In London there was consternation over Irish agitation for repeal of the Act of Union, reports of violence directed against landlords and the attempted rising by the Young Irelanders.

[6] While he was to commute the sentences of the Young Ireland conspirators from hanging to life transportation, Clarendon did take stringent security measures, proclaiming martial law in large parts of the country and persuading Westminster to suspend Habeas Corpus.

In 1849, he sided with Catholic bishops in their objections to a non-denominational ("godless") scheme for higher education, and when an official inquiry failed to indict the Orange Order for the death of 20 Catholics in the Dolly's Brae affray, he dismissed the magistrate concerned, Lord Roden, and helped bring in the Party Processions Act (1850) to curtail the Protestant association.

[6] His services were expressly acknowledged in the Queen's Speech to both Houses of Parliament in September 1848 - this being the first time that any civil servant obtained that honour; and he was made a Knight of the Garter (retaining also the Grand Cross of the Bath by special order) on 23 March 1849.

Clarendon was not responsible for starting the war, but he supported it and maintained close relations with the French Emperor Napoleon III, and the Empress Eugenie, whom he had known in Spain from her childhood.

[3] On 4 June 1839, Villiers married the widowed Lady Katherine Foster-Barham (a daughter of James Grimston, 1st Earl of Verulam) and they had eight children:[1]