One question I asked myself as I began plotting the book was "what happened after the Napoleonic Wars?" Sure, there was the Vienna Conferences and all that, but surely foreign policy didn't stop in the 1820s. The answer to my question was that Britain devoted to their interests on the European Continent, primarily in the eastern region because it was so unstable in the wake of Napoleon's defeat. Kingdoms were restructured, some were even eliminated, and there was a strong nationalist movement throughout the continent.
The Eastern Question focused on what the west was going to do about an unstable eastern European arena plus and unstable Turkey in the face an empire minded Russia. The balance of power in Europe made this an important consideration in order to avoid another Napoleon. Also, it was important because the Eastern theatre represented a huge economic opportunity as well as the avenue for lucrative trade routes into Asia Minor and India.
Britain's largest concern was figuring out how to protect their access to the Dardanelle Straits in Turkey. Valerian is heavily involved in this effort during his years abroad.