The Association of Southeast Asian Nations (ASEAN) was founded in 1967 by Thailand, Indonesia, Malaysia, the Philippines and Singapore to promote economic growth, social progress and political stability. Today, the number of members has grown to ten countries with around 575 million inhabitants, or around eight percent of the world's population.

Meetings have been held irregularly since 1976 and have been extended to several summits per year since the mid-1990s. The focus is always on the unity of the member states and common goals.

In addition to these summit meetings, the association regularly informs itself in smaller delegations about political, economic and social developments worldwide in order to benefit from the experiences of others in its region.

On January 30, 2007, Lord Mayor Diehl welcomed a delegation of Southeast Asians to Wiesbaden City Hall as part of such a consultation. He praised the association's commitment to stability. The ASEAN ambassadors expressed their thanks for the warm welcome they received in the Hessian state capital and then signed the city's Golden Book.