A Catholic convert, Melfort and his brother the Earl of Perth consistently urged James not to compromise with his opponents, contributing to his increasing isolation and ultimate deposition in the 1688 Glorious Revolution.

[citation needed] Lauderdale was the Crown's representative in Scotland and marriage to his niece brought Melfort lands and positions; in September 1673, he received a commission as Captain in the Foot Guards.

As a result, James often pursued policies in Scotland based on information either out of date or wrong, most significantly that acceptance of his personal beliefs did not extend to Catholicism in general.

His 'tolerance' measures were badly timed, particularly when the October 1685 Edict of Fontainebleau revoked it for French Huguenots, reinforcing fears Protestant Europe was threatened by a French-led Catholic counter-reformation.

The religious divides of the 17th century meant many Scots saw concessions as potentially destabilising, which resulted in the rapid collapse of the 1685 Argyll and Monmouth Rebellions.

Melfort left London on 3 December 1688 with his wife Euphemia and the seven children of his second marriage; a few days later, he arrived at Saint-Germain-en-Laye outside Paris, location of the exiled court for the next 25 years.

In order to weaken his opponents, Louis provided James military support to regain his kingdoms and in March 1689, he landed in Ireland, with Melfort as Secretary of State.

The Scottish Convention was meeting in Edinburgh and when it opened on 16 March, a letter drafted by Melfort was read out, demanding obedience and threatening punishment for noncompliance.

[21] Although committed Jacobites were a tiny minority, many Scots were unenthusiastic about the alternatives; the letter caused public anger and demonstrated James had learned nothing from the events that led to his deposition.

The tone reflected an internal Jacobite dispute between the Protestant 'Compounders', who viewed concessions as essential to regain the throne, and the mostly-Catholic 'Non-Compounders' like Melfort, who urged him to refuse any.

[22] Melfort consistently prioritised England and Scotland over Ireland, leading to clashes with the Irish Jacobite leader, the Earl of Tyrconnell, and the French ambassador, the comte d'Avaux.

He was allowed to return to St Germain in 1697, but his political career was effectively over, as was confirmed in 1701 when a letter written to his brother was misdirected to London, leading to accusations of treachery.