[1] Almost immediately after leaving Cambridge Spencer was elected to parliament for South Northamptonshire as a Liberal, before departing for a tour of North America.

Spencer split from other whiggish aristocratic Liberals in 1866 on the issue of Russell's reform bill, which he supported, and his loyalty was rewarded by his appointment as Lord Lieutenant of Ireland when Gladstone returned to power in 1868.

Spencer, in fact, went further than most of his ministerial colleagues, including Gladstone himself, in arguing for the setting up of government tribunals to enforce fair rents on Irish landlords (a reform which would eventually be introduced by the Land Law (Ireland) Act 1881).

In May 1882, Gladstone's decision to release the Irish Nationalist leader Charles Stewart Parnell from prison led to the resignation of the hardline Chief Secretary for Ireland, W. E. Forster.

He attracted heavy criticism for his poor handling of a group of murders in Maamtrasna – one of the supposed criminals, Myles Joyce, had been hanged while still proclaiming his innocence, leading to a great deal of condemnation of Spencer from Irish Nationalist sources.

By 1885, Gladstone's second government was in a very weak position, largely as a result of the death of Charles Gordon, and Spencer's efforts to renew the Irish Crimes Act and secure passage of a land purchase bill ran into opposition from the radicals in the Cabinet - Joseph Chamberlain and Sir Charles Dilke - who hoped to use the opportunity of the legislation to pass a greater measure of local self-government for Ireland.

During the interval between the fall of Gladstone's second government and the beginning of his third, in February 1886, Spencer became a convert to Irish Home Rule, unlike most of the other leading Whigs, who deserted to Liberal Unionism.

Spencer's position on home rule led to his social ostracism by other members of his class, including the Queen herself, and spent much of his period in opposition getting his personal finances in order.

However, on 11 October of that year he suffered a major stroke which ended his political career, only two months shy of the Liberals' return to power.

[4] The War Office issued a Circular Letter on 12 May inviting volunteers, and within three days Spencer had offered to raise a company from his tenants at Althorp.

[5][6][7] The 1st Northampton RVC sang a song to the tune of The British Grenadiers: After the separate Northamptonshire RVCs were formed into an administrative battalion the following year, Spencer was promoted to major on 2 April 1861.

[14] In 1865 Spencer chaired a royal commission on cattle plague, alongside Lord Cranborne, Robert Lowe and Lyon Playfair.