@Lechiffre55: I know in the UK the Tories do long spells in charge but Blair and Brown also had a nice long spell at the helm. It does flip back and forth, even if it takes some time to flip. Has Scotland ever not been under the thumb of the SNP?
Yes, absolutely! I'm not having a go, as I know you said you don't know Scottish politics well, but it's a funny question from a Scottish perspective because until sometime in the 2000s - 2010s, Scotland was Labour-dominated for about a century. And before that it was dominated by other socialist/workers' parties, some of whom were pro independence. The SNP have been around for ages - won their first seat at Westminster in 1967 and kept up a small presence, but their status as the third largest party (overtaking the Lib Dems) didn't happen until 2015.
I was living abroad in 2010, when the UK election was held which kicked out Gordon Brown and consigned the whole UK to fifteen years of Conservative rule. I remember being surprised that in terms of MPs elected, Scotland broke into (roughly) thirds: Labour, Lib Dem, SNP. I was surprised to see the SNP figuring significantly outside of the Highlands and Islands. I think that's where the Scotland-wide balance started to shift - with the Holyrood election of 2007 and the UK election of 2010. But there was an even bigger shift after the 2014 Scottish Independence Referendum, which in my view was wildly botched by both Labour and the Conservatives who, rather than taking the referendum mandate and the 45% "Yes" result as a warning shot took it as an admission of defeat from Scottish separatists (and, to some extent, Scottish devolutionists). It wasn't, and the triumphalism that followed - EVEL and so on - galvanised support for the SNP.
I'm in a Glasgow (city) constituency where Labour was long dominant, and I grew up in the constituency next door, where my family still live. In both of these, the balance tipped in the 2015 UK election - AFTER the referendum. Both constituencies had been Labour safe seats for a century, and both flipped SNP in 2015 and have stayed SNP. In both of these constituencies, which should be target "swing seats", Labour has not run a competent candidate since the 2015 flip - why on earth not?
RE 21st century Scottish politics, ArabellaScott posted a great link upthread, but for an even quicker "potted history": the Scottish Parliament has existed since 1999, following two referndums where the majority approved a devolved Scottish Assembly and Executive - now a Parliament and a Government. Independence supporters (including but not limited to the SNP) wanted and fought for it, but its main and decisive advocate was Labour - who didn't want an independent Scotland, but wanted devolution.
From 1999 to 2007, Scotland had Labour-led coalition governments with the Lib Dems as junior partner. In 2007, the balance flipped and the SNP won the largest number of seats; they opted for a minority government. In 2011, the SNP won an outright majority. When Alex Salmond (boo! hiss!) resigned after the no vote in the 2014 independence referendum, Nicola Sturgeon became FM. In 2016, the SNP lost their majority but still got the highest number of seats, so formed another minority government. In 2021, the SNP gained a few seats but still not a majority and formed a coalition government with the Greens.
So SNP dominates for now - and the focus is on who they will elect as Leader, and if that person becomes FM. It's interesting to look at the composition of Holyrood today (there are 129 seats): SNP 64, Con 31, Lab 22, Greens 7, Lib Dems 4 + Presiding Officer 1 who only votes to break a tie. Interesting times!