Alternate History is a form of fiction where an event in history turns out differently to what actually happened. Steampunk covers a multitude of stories but can be defined as Science Fiction as seen by the Victorians, it usually has airships, corsets and brass goggles and often contains supernatural elements as well as Science Fiction. The Voidships universe takes a single scientific change to create a history that's both familiar and different.
In the Voidships universe, in 1843, the scientist Faraday demonstrates the partial nullification of gravity to his assembled colleagues at the Royal Institute in London. It's a discovery that changes the world.
The stories written in the Voidships universe take place 50 to 70 years later, the British Empire is at its height but war looms on all sides.