Britain, France and the United States used a range of weaponry to strike targets in Syria.
The strikes began at 2am BST and destroyed important infrastructure at three sites connected to the Syrian regime's chemical weapons programme, according to the allies.
Here's the weaponry the countries employed:
Britain - Tornado GR4
Four Tornado GR4s were Britain’s contribution to the operation.
The Tornado has been carrying out air strikes in Syria and Iraq over the past few years.
Set to be retired from service next year, after almost four decades on operations, the Tornado, with a maximum speed of Mach 1.3, has also seen action in Libya, Afghanistan and Iraq.
It can be loaded with a mix of weapons which include Paveway II, III and IV series GPS/laser-guided bombs, Brimstone air-to-ground missiles and Storm Shadow air-launched long-range strike missiles.
The main Tornado squadrons are based at RAF Marham in Norfolk, which will become the new home of the cutting-edge of the F-35 Lightning stealth fighter jets.
There are currently eight of the jets based at RAF Akrotiri, Cyprus, a location some 200 miles from Syria.
France - Rafale jets
The main firepower for the Armée de l'Air comes from the Rafale and Mirage 2000 variants, of which they have a combined 212 jets.
The French defence minister, Florence Parly, said Rafale jets flew from France to strike their targets in Syria.
It can also be armed with Storm Shadow.
The office of French President Emmanuel Macron posted video on Twitter of one of the jets taking off before the operation.
Storm Shadow Cruise Missiles
The Tornado jets each fired two Storm Shadow missiles to strike their targets.
Weighing in at 2,866lb (1,300kg), measuring 16.7ft (5.1m) in length and with a range in excess of 150 miles (240km), it is operated from Tornado jets and in future will be carried on Eurofighter Typhoon.
Its range means that the jets involved would not have been required to fly far from Cyprus may not have entered Syrian airspace.
Described as a "long-range deep-strike weapon" by MBDA systems, which produces the missile, the company states on its website that it is "designed to meet the demanding requirements of pre-planned attacks against high-value fixed or stationary targets".
The long-range air-to-surface missile, designed as a "bunker buster”.
It was first brought into service in 2003 and has previously been described by the RAF as "arguably the most advanced weapon of its kind in the world".
US defence officials have not released information on what missiles it used during the operation.
However, is widely reported that the Tomahawk Land Attack Missile may have been the weapon of choice.
With the missiles reportedly being launched from the eastern Mediterranean Sea.
The Tomahawk is carried by British and US ships alike and can deliver a 1,000-pound warhead with a range of 800 - 1,500 miles.
This video from a missile attack on Syria last year shows what a Tomahawk launch looks like:
Missile de Croisière Naval
The French navy were also involved.
Its multimission frigates reportedly fired MdCN (Missile de Croisière Naval) cruise missiles.
The details of this weapon are not made public.
United States B-1 Bombers
The US also deployed B-1B Lancer long-range bombers, a US official has been quoted as saying.
The four-engine B-1 can launch JASSM cruise missiles which carry 1,000-pound warheads with a range of more than 230 miles.
It is possible that these would have flown from Al Udeid, Qatar.