The Starlight initiative picks up the legacy of several experiences, either accomplished or in progress, in defence of the night sky all over the
world, such as:

• Last decade's International meetings and declarations in defence of night sky such as: Universal Declaration of Human Rights for Future Generations (1999) or the Venice Declaration (2002).

• The re-encounter of tangible and intangible cultural heritage induced by astronomy and the feelings that star observation aroused in all cultures through the history of mankind. This rediscovery has been expressed by experiences such as the "Thematic Initiative Astronomy and World Heritage" launched by UNESCO in 2003, the appearance of new branches of knowledge like archaeoastronomy and the INSAP (Inspiration of Astronomical Phenomena) meetings.

• Increasing scientific activity and initiatives alerting to the effect of light pollution or artificial night lighting on some species or ecosystems, leading to consider attentively night's ecological dimension: life expresses itself 24 hours a day. An example is given by the work developed by Parks Canada, towards the control of outdoor lighting and the reduction of light pollution in national parks, endorsing the needs for protection of nocturnal ecology and for more science in that field.

• Increasing recognition of starry night skies and natural darkness as the main factor of threatened nocturnal landscapes, both in remarkable cultural spaces and in protected natural areas. This new sensibility is expressed through initiatives such as "Natural Lightscapes" protection (US-NPS) and the first recognitions of "night landscapes" by the European Landscape Convention.

• The foundation of International associations and initiatives in defence of the increasing light pollution such as the International Dark Sky Association, leading very active and enriching experiences, and the development of the first maps showing the lavish use of lighting in several areas of our planet.

• The progressive inclusion of the defence of sky quality into initiatives dealing with energy efficiency promotion and clean energy development as vectors to reduce light pollution and atmospheric emissions: Kyoto and beyond. Energy sustainability and night sky protection go hand in hand in initiatives such as greenlight projects or the European design competition "Lights of the Future".

• The flourishing of laws aimed at night sky protection, together with new regulations and codes fighting against light pollution. Originally limited to areas close to astrophysical observatories, they have nowadays spread to towns and inhabited rural areas, which claim the common right of a clear night sky, as a factor of quality of life and health, to regain the everyday culture of observing a starry sky.

• The creation of technical offices and bodies aimed at the protection of astronomic observation areas from atmospheric, radio-electric and light pollution, such as the IAC's Technical Office for the Protection of the Quality of the Sky del IAC, the Light Pollution Science and Technology Institute, and the OPCC in Chile, whose results allowed some important changes in the technological and industrial fields, as it is shown by the advances supported and registered by the CIE (International Lighting Commission).

• The increasing recognition of the night sky as a sustainable development asset and resource, expressed through  new initiatives in observation-related tourism and the new role of the astronomy-related knowledge tourism.