Lots of other resources such as gold, iron, coal, trade routes, etc. Oil and gas came into play in the Caucuses region around 1900. A cheaper way to trade with the East was always a priority for the British. For the Germans, they were most interested in Russian dominated Eastern Europe. Keep in mind that all of Poland, Ukraine, the Baltics, Finland, Georgia, Azerbaijan, Turkmenistan, and the Central Asian states were in the hands of Russia. It was even larger then than it is today. Many of these regions were great for trade and food production as well. Also, more subjects and territory, more tax revenue.