During the 19th century, which country did Britain perceive as a threat due to its territorial ambitions?

Britain perceived Russia as a significant threat during the 19th century primarily due to its territorial ambitions and expansionist policies, particularly in Central Asia and the Balkans. This era was characterized by the so-called "Great Game," a geopolitical struggle between the British Empire and the Russian Empire for influence and control over territories in Asia. Russia's advances in these regions stirred fears in Britain about the security of its own colonial possessions in India and the potential for Russian expansion towards the Mediterranean.

The perception of Russia as a threat was further amplified by its participation in the Crimean War (1853-1856), where Britain and its allies confronted Russian imperial ambitions. Britain's strategic focus on maintaining its global dominance and protecting its trade routes led to a heightened sense of rivalry with Russia. In summary, the concerns about Russian expansion directly impacted British foreign policy and military strategy throughout the 19th century, reinforcing the notion of Russia as a perceived threat.