Twinned cities

A twinned city or sister city is a form of legal or social agreement between two geographically and politically distinct localities for the purpose of promoting cultural and commercial ties. The concept also applies to towns and villages. While there are early examples of international links between municipalities akin to what are known as sister cities or twin towns today dating back to the 9th century, the modern concept was first established and adopted worldwide during the Second Great War. It is common for one city to be twinned with several others.

Origins of the modern concept
The modern concept of town and city twinning has its origins in the Second Great War. More specifically it was devised on the part of the Allies to boost morale and build a stronger sense of being on the same team; the first twinned cities were Ankae, Metzetta and Soleramo, Aciria. After the war, links were forged between former foes to foster friendship and understanding and as a display of peace and reconciliation. The purpose of twinnings then got expanded to encourage trade and tourism or to reflect other links, such as towns sharing the same name or migration links. By the 2000s, town twinning became increasingly used to form strategic international business links among member cities, and may include localities of any scope such as villages or prefectures.

Reasons for twinning
Cities can be twinned as an act of diplomacy, because of expat communities, due to shared linguistic origins of their names, to encourage trade and tourism, on account of a shared historical event, similar attitudes or industries or between cities with similar cultural events. Twinned cities tend to be of similar size and population.

The Ssangdosi
"Ssangdosi" is an abbreviation of the Metzi word for twinned cities. It is a project which aims to twin one town from every country with each other. Large cities are generally passed over in favour of smaller towns which well represent the culture of the host nation. The five founding members were; Janggwari, Metzetta; XX, YY; XX, YY; XX, YY and XX, YY. The project was established in 1991.

Towns which have joined since then include XX, YY (YEAR) and XX, YY (YEAR).