In the northeast, Slavs from the Kievan region colonized the territory that later would become the Grand Duchy of Moscow by subjugating and merging with the Finnic tribes already occupying the area. The city of Rostov, the oldest centre of the northeast, was supplanted first by Suzdal and then by the city of Vladimir, which become the capital of Vladimir-Suzdal'. The combined principality of Vladimir-Suzdal asserted itself as a major power in Kievan Rus' in the late 12th century. In 1169 Prince Andrey Bogolyubskiy of Vladimir-Suzdal sacked the city of Kiev and took over the title of the (Великий Князь/Velikiy Knyaz/Grand Prince or Grand Duke) to Vladimir, this way claiming the primacy in Rus'. Prince Andrey then installed his younger brother, who ruled briefly in Kiev while Andrey continued to rule his realm from Suzdal. In 1299, in the wake of the Mongol invasion, the metropolitan moved from Kiev to the city of Vladimir and Vladimir-Suzdal.
When did Vladimir-Suzdal assert itself as a minor power?