Nature of prominences and their role in space weather : proceedings of the 300th symposium of the International Astronomical Union held in Paris France June 10 16 2013 Solar prominences and filaments are large gaseous features extending outward hundreds of thousands of kilometres from the Suns surface which play an active role in space weather. Magnetic clouds and interplanetary coronal mass ejections associated with erupting prominences can produce severe perturbations in the Earths near space environment. IAU Symposium 300 presents a review of the state of the art theoretical and numerical modelling of prominences and filaments and their role in the dynamics of Sun Earth relations. Observations from the latest international space borne missions (Hinode STEREO and SDO) and ground based observatories are presented. The Symposium benefits not just newcomers to solar physics research but it shares the current status of our sophisticated solar analysis with the stellar community now that huge prominences and CMEs have been detected in solar type stars and others which will affect any exoplanets they host.