Before 1832 the only people who could “vote” in Scotland, for the few members of parliament, were the landowners and the merchants/burgesses in the burghs, like Forfar - in total about 4,000 people. Some of these constituencies, however, were controlled by the local Lord or Earl who chose the MP to represent the area. The 1832 and 1868 reform Acts substantially increased the voting population and by 1885 about 50% of the males resident in Scotland could vote.
The Liberal Party dominated Scottish politics, but there was also an important Unionist party - that eventually merged with the Conservative party.
From the inspirational leadership of Keir Hardy, the Labor party emerged as a force in the 1920’s and started a steady drift to popular left-wing politics in the more populated mining and industrial areas. Scotland even elected a few communist members of parliament in the 1930’s and 1940”s.
The Scottish National party started in the 1930’s, but only started to become a force after 1967, with growing strength and broad support through to today’s domination of the political scene in Scotland.
The Conservative party has steadily declined in importance and now to the point of irrelevance on the Scottish political scene.