The strength of your economy determines the course of your game and your offensive strategy. You must pay and feed your troops, replace their losses and recruit new brigades. You must build factories for trade goods. You have to grow enough food and make enough wine for your population and sailors as well as quarry stone and fell lumber for fortresses and ships. You have to link this all together to build a successful, well supported army or fleet to protect your buoyant economy… or you can invade your neighbours territory and capture their mills and factories.
The nations of Europe have always needed to trade to survive. Austerlitz features all the major European and colonial trade centres of the period which buy and sell everything you need! Use merchant ships and baggage trains goods you can’t produce on home soil from all around the globe. Or trade with allies to support your economies. But who will set the fair price?