History of piracy on the high seas

The image of the wild and fearsome pirate captain has often captured Hollywood's imagination, but piracy is a very real and increasing problem for modern sea-farers.

* Roman emperor Julius Caesar is said to have been an early victim of pirates - captured on a voyage across the Aegean Sea. It is said that he demanded they double his ransom from 20 talents of gold to reflect his worth.

* The Viking raiders who terrorised northern Europe started out as pirates, attacking ships at sea, before turning their attentions to pillaging coastal settlements.

* The largely fictional swashbuckling buccaneers who capture the modern imagination have their roots in the pirates who reigned in the waters of the Caribbean in the 17th century. Many of them arrived in the area after the War of the Spanish Succession.

* Johnny Depp's character, Captain Jack Sparrow in the Hollywood blockbuster Pirates of the Caribbean owes more to modern-day rock stars than historical fact. But Blackbeard, a feared character with wild black hair and a ragged beard, did hold a reign of fear over the Caribbean seas and the Atlantic Ocean around the mid 1700s..

* He is thought to have been British, probably born before 1690 as Edward Teach. He learned his robbery techniques serving on a British privateer - armed ships hired by the Government of the day - where he was allowed to keep whatever spoils of war he managed to gather.

* But there is nothing romantic about the reality of modern piracy. In 2008 nine innocent crewmembers were killed in pirate attacks and nine are missing, presumed dead. A total of 581 have been taken hostage and nine have been kidnapped.

* Somalia is among the world's worst piracy hotspots and the pirates in the region are responsible for more than a third of all attacks.

* The International Maritime Bureau, the recording body for piracy, estimates that over 1,200 Somalis and at least six major groups are involved.

* More than 10 vessels and 250 crew are thought to currently be in the hands of pirates - who are waiting for ransom to be paid by the ship's owners.

* The average ransom earned for a ship by pirates has risen dramatically in recent years, say experts, from US dollars 10,000 to US dollars 1 million.

* Modern pirates are well armed and well organised. Many, particularly Somali gangs, are using larger "mother ships" to reach deeper ocean waters before creeping up on ships with smaller boats and boarding them using grappling hooks and ladders.

* A developing hotspot is the Gulf of Aden where experts are worried by the rising number of attacks by Somali pirates.

* All vessels in the area are now being advised to take maintain strict 24 hours radar and anti piracy watch. Some captains are protecting their boats with electrified "fencing" and satellite tracking.