Battleships intended for conquering and domination at sea were the heart of the navy from the mid-17th century onwards. They featured the most powerful weapons and the highest degree of manoeuvrability.European ships with rectangular rigging were unusually fast for sailing ships. Thanks to their high sides, these ships could withstand heavy weather. However, they were strongly dependent on wind. In time, their rigging was improved and their displacement increased. The improved vessels were armed with artillery placed at the sides. Before a battle, ships would form a line which crumbled in combat, turning the battle into a chaotic scramble. Artillery was used inefficiently and vessels often prevented each other from firing. Small ships packed full with explosives and inflammables drifted down wind to their targets. Amazingly, some battles were actually won thanks to them.