On April 2, 1916, a new kind of terror hovered over Scotland's capital as the dreaded air raids taking place along various English coastal towns moved north for the first time.

Four German Zeppelin airships set out to raid the Firth of Forth, and especially the naval base at Rosyth and the Forth Bridge, but only two would make it to the Scottish east coast on that April evening, with two troubled by engine failure and poor navigation.

According to a local police report of the time, the first order was given from the military authorities to "take air raid action" at 7pm on April 2.

All off-duty police officers were turned out, the lights were lowered and the trams stopped.

Just five hours later, at 11.50pm, the first reports of a bomb exploding in the direction of Leith were made.

For the next 35 minutes, a new kind of warfare played out as 24 bombs fell across the city, killing 13 and injuring 24.

It was the first time a war had been brought on to home soil in many years explains Ian Brown, aviation curator with the National Museum of Scotland, based at the National Museum of Flight in East Fortune, East Lothian.

"When you think about bombings and air raids, you tend to think of the Second World War but actually it was far worse for Edinburgh in the First World War," he says.

"Wars had been things that happened somewhere else and now, suddenly, it was happening at the end of their street and for some people, their houses were bombed so it very much brought the war home.

"The idea would have been to attack military targets and to cause panic. If you can upset civilian areas and cause panic then it would have put pressure on the government and the military to pull troops back from the Western Front and man the home defences.

"Because by that stage in the war both sides were looking at ways of trying to create a deadlock on the Western Front."

With no air raid shelters at the time, Edinburgh's citizens had little protection from the falling bombs.

In one home at 16 Marshall Street, three people were killed while standing in the open doorway on the ground floor.

They were facing the street when the bomb fell in the front door. The impact from this particular blast also killed one man who was on the opposite side of the street.

Newspaper reports following the raid also noted how others had made a lucky escape after an explosive bomb struck the roof of a property on Marchmont Crescent, piercing right through to the ground floor.

This bomb failed to explode and it is believed to be the very same one the National Museum of Flight has on display.

"There weren't air raid shelter or sirens," Ian says. "A lot of people went and stood out on the street. They would look to see what was happening, which is probably the worst thing you could do.

"There was actually an aircraft that took off from East Fortune but it was completely dark and they had no search lights because they weren't expecting an attack.

"It couldn't see the airships, never mind open fire on them. So it turned back and the pilot [Flight sub-Lieutenant GA Cox] got badly injured because he crashed the aircraft on landing.

"We weren't able to attack them at all and lost an aircraft in the process."

While lives were lost in Scotland's first air raid, the city also had some near misses, with one bomb failing to hit target of Edinburgh Castle and instead falling on the Castle Rock.

Today, a flagstone on the Grassmarket, an area where almost all of the windows in the local shop fronts were shattered by the bombs, commemorates the air raid.

"I think hardly anyone in Edinburgh remembers it now," Ian says. "One hundred years on, it is out of living memory.

"The blitz in the Second World War, there are documentaries on just about every night about it, and it is fairly well covered in Hollywood movies.

"But the bombing of Britain in the First World War, there are very few people have heard about it never mind remember the details, so there is a forgotten aspect.

"The First World War is often thought of as fought in the trenches of France and Belgium but actually there's a lot a more to it than that."