Created in 1899, the PCA is the world's oldest inter-governmental body that organizes arbitral tribunals to resolve disputes among its 121 member states.
The Philippines brought a case in 2013 to the UNCLOS tribunal, contesting China's claims and activity in the South China Sea, saying that they were contrary to worldwide law.
A Filipino soldier patrols the shore of Pagasa Island (Thitu Island) in the Spratly group of islands in the South China Sea, west of Palawan, the Philippines, on May 11, 2015.
(AP Photo/Bullit Marquez). In this photo taken March 29, 2014, a Philippine flag flutters from the deck of the Philippine Navy ship LT 57 Sierra Madre off Second Thomas Shoal in the South China Sea. They called their campaign to push China out of the South China Sea, "CHexit" or "China exit now".
Chinese fisherman had also killed endangered sea turtles and giant clams "on a substantial scale" - with the full knowledge of China, the tribunal found. The ministry repeated China's often-expressed stance that the Philippines' move to initiate arbitration without China's consent was in "bad faith" and in violation of global law.
First, the Philippines asked for a ruling on the status of the so-called "Nine-Dash Line", a demarcation that China has used to substantiate its "historic rights claim" to parts of the larger waterway. It says it does not acknowledge the tribunal's jurisdiction, and will not accept its ruling.
- The body, based in the neo-Gothic extravagance of the Peace Palace in The Hague, has no enforcement powers.
Townshend said that China could begin construction work on Scarborough Shoal - an outcrop it now controls 100 miles from the Philippines and 500 miles from China - or set up an air defense zone over the South China Sea.
China claims about 90 per cent of the South China Sea, including reefs and islands, which are also claimed by others.
China's uses a nine-dash line drawn on a 1940s map to claim almost all the South China Sea. These include one which claims that Scarborough Shoal and three reefs are not islands capable of sustaining economic activity and therefore not entitled to an exclusive economic zone (EEZ), and another one which claims that five other reefs are low-tide elevations and therefore not entitled to a territorial sea or EEZ. Japan and the United States are concerned tension will spike in the region as China reacts to the ruling.
However a new Philippine leader who appears friendlier to Beijing could also influence the aftermath of the ruling.
China has summoned its demobilized sailors and officers for training drills, state media have confirmed, in exercises that apparently started just days ahead of a tribunal ruling on China's expansive claims to the South China Sea.
- China, which is boycotting proceedings in the South China Sea case, declined to appoint an arbitrator.
"It will mobilise all possible support from other countries to back up its position and continue to carry out manoeuvres in the South China Sea".