From potential modularity to the level 1 weight 2 case of the conjectures of Fontaine-Mazur and Serre Abstract: I will explain how from the results of Taylor of potential modularity of Galois representations one can deduce a result of "existence of a family" containing certain p-adic Galois representations, and deduce from this the level 1 weight 2 case (and other cases of small ramification) of the conjecture of Fontaine-Mazur-Langlands (FML), and also the FML conjecture for "elliptic curves". Finally, using again potential modularity and lowering the level for Hilbert modular forms I will explain how a result of "existence of minimal deformations" can be obtained, at least in the semistable case, thus reducing the proof of some semistable cases of Serre's conjecture to the proof of the FML conjecture in the same case, therefore in particular proving Serre's conjecture in the level 1 weight 2 case and other cases of small ramification (remark: a similar result has been proved independently by Khare and Wintenberger).