Dreadlocks, also known as locs or dreads, are rope-like strands of hair formed by locking or braiding hair. Origins
Some of the earliest depictions of dreadlocks date back as far as 1600–1500 BCE in the Minoan Civilization, one of Europes earliest civilizations, centred in Crete (now part of Greece). Frescoes discovered on the Aegean island of Thera (modern Santorini, Greece) depict individuals with long braided hair or long dreadlocks.In ancient Egypt, examples of Egyptians wearing locked hairstyles and wigs have appeared on bas-reliefs, statuary and other artifacts. Mummified remains of Egyptians with locked wigs have also been recovered from archaeological sites.During the Bronze and Iron Ages, many peoples in the Near East, Anatolia, Caucasus, East Mediterranean and North Africa such as the Sumerians, Elamites and Ancient Egyptians were depicted in art with braided or plaited hair and beards. However, braids are not dreadlocks, and it is not always possible to tell from these images which are being depicted. Etymology
The history of the name "dreadlocks" is unclear. Some authors have speculated that the "dread" component could refer to the reaction of British soldiers upon encountering Mau Mau fighters who had this hairstyle. History
In Ancient Greece, kouros sculptures from the archaic period depict men wearing dreadlocks.The style was worn by Ancient Christian Ascetics in the Middle East and Mediterranean, and the Dervishes of Islam, among others.
Guinness Book of World Records
On 10 December 2010, the Guinness Book of World Records rested its "longest dreadlocks" category after investigation of its first and only female title holder, Asha Mandela, with this official statement:

Following a review of our guidelines for the longest dreadlock, we have taken expert advice and made the decision to rest this category. The reason for this is that it is difficult, and in many cases impossible, to measure the authenticity of the locks due to expert methods employed in the attachment of hair extensions/re-attachment of broken off dreadlocks. Effectively the dreadlock can become an extension and therefore impossible to adjudicate accurately. It is for this reason Guinness World Records has decided to rest the category and will no longer be monitoring the category for longest dreadlock. See also
Box braids
Bob Marley
Elflock
Cornrows
French braid
Polish plait

Notes
References
Kroemer, K. (2001). Ergonomics: How to Design for Ease and Efficiency (2nd ed.). Englewood Cliffs: Prentice Hall. ISBN 0137524781. Tacitus, Publius (or Gaius) Cornelius. De vita et moribus Iulii Agricolae. External links

 Media related to Dreadlocks at Wikimedia Commons
Dreadlocks Story – Documentary by Linda Aïnouche
Guardian article
 The dictionary definition of dreadlocks at Wiktionary