The United Kindom of Great Britain and Ireland, 1836-1901 (although this is usually extended to 1705-1914). A period of Great prosperity as Britains' second empire (the only remnants of the medievel empire after the end of the hundred years war decision in 1556 were the Channel Islands) came of age. Along with the starting points of joining England & wales with Scotland in 1705, the new empire set about restoring lands lost after the "Golden age", and this was overseen by Queen Victoria. Due to the fact that the poor were suppressed while the rich grew very rich and well educated with beautiful accents (like myself), the stereotype of the posh-Brit grew. This empire was practically gone by 1965, although this had been seen by Churchill as early as the end of world war I. However, in this time Britain became the largest superpower ever known. Off the back of what seemed and invincible navy, a skilled army and even the worlds' first air force (with air balloons, albeit), this mighty roaring lion seemed untameable until drawn into war with other superpowers, which allowed a weak-by-comparison nation (USA) to become powerful.
Victorian Britain was a reflection of the affluence of Britain, which was in control of itself, its' neighbour Ireland and had its' enemies on a leash for the most part.