 Wider co-operation between the Habsburgs was limited, since their objectives did not always align; Spain was a global maritime power, Austria primarily a European land power.The Empire had over 1,800 members, most extremely small; although a Habsburg had been Holy Roman Emperor since 1440, in theory it was an elected position.After 1555, the Empire increasingly became a federation of independent states; encouraged by France, Habsburg acceptance of this reality is one of the less acknowledged outcomes of the 1648 Treaty of Westphalia.