The Plan of Campaign was a stratagem adopted in Ireland between 1886 and 1891, co-ordinated by Irish politicians for the benefit of tenant farmers, against mainly absentee and rack-rent landlords.
It was launched to counter agricultural distress caused by the continual depression in prices of dairy products and cattle from the mid-1870s, which left many tenants in arrears with rent.
It was outlined in an article headed Plan of Campaign by Harrington which was published on 23 October 1886 in the League's newspaper, the United Irishman of which O'Brien was editor.
The election in November saw Parnell with 86 seats holding the balance of power in the House of Commons, and continuing to give loose support to Lord Salisbury's Conservative government.
William Gladstone, leader of the Liberal Party committed himself like a ferocious evangelist to introducing Home Rule as "justice for Ireland".
Parnell switched the support of his MPs to the Liberals; Gladstone formed his third government and then introduced the First Irish Home Rule Bill in April 1886.
Dillon and O'Brien were arrested, and, when their supporters started a public defence fund, Archbishop Croke issued a No Tax Manifesto which prompted Balfour to consider imprisoning him also.
The rising crime rate and general unrest forced Balfour to more subtle strategies by seeking Vatican assistance to suppress clergymen involved in the Plan.
In answer Pope Leo XIII despatched Archbishop Persico to Ireland, who travelled throughout the country from July 1887 until January 1888, consulting prominent members of the hierarchy.
The covering letter with the encyclical was written by Raffaele Monaco La Valletta, Cardinal Secretary of the Holy Office, and included: "The promulgation of the Papal Rescript, condemning boycotting and the Plan of Campaign as grave offences against the moral law, took Mgr.
Persico as much by surprise as it did Cardinal Manning; for both he and the Papal Delegate confidently expected that, in accordance with their joint suggestions, the condemnation of the immoral methods of the League would have been pronounced not directly by the Holy See, but by the Irish Episcopate.
Persico later commented, "I had no idea that anything had been done about Irish affairs, much less thought that some questions had been referred to the Holy Office, and the first knowledge I had of the decree was on the morning of the 28th April, when I received the bare circular sent me by Propaganda.
By this time Parnell had been induced to give some support which helped in the formation of a Tenants' Defence Association in Tipperary and this, along with Dillon's raised money, enabled the Plan to continue.
The organisers were forced to seek financial assistance elsewhere and Dillon embarked on a fund-raising drive in Australia and New Zealand (May 1889 – April 1890) which raised some £33,000, but this was insufficient for their needs.
In October Dillon and O'Brien jumped bail and escaped to France, and from there to America where they were empowered by Parnell to raise more money (£61,000, which he intended for the Irish party).
While the main outcome was very favourable to him, much of the surrounding evidence suggested that the organisers of the Campaign and the former Land War had incited, or were complicit in, the attendant violence.
As Balfour had hoped, the organisers found it difficult to raise enough money to pay stipends to those evicted during the Campaign and now forced to live on party doles.
The Campaign attracted many British and foreign journalists to Ireland as well as Liberal MPs some of whom were imprisoned under the Coercion Acts, which increased sympathy for Home Rule.
His approach, much in keeping with his character, had been from the beginning two-pronged – I shall be as relentless as Cromwell in enforcing obedience to the law, but, at the same time, I shall be as radical as any reformer in redressing grievances and especially in removing every cause of complaint in regard to the land.