1 INTRODUCTION  
2 DATA  
2.1 Weak Lensing: CFHTLS  
2.2 X-ray: XMM-LSS  
3 METHOD  
3.1 Weak Lensing Cluster Detection  
3.2 X-ray Cluster Detection and Analysis  
4 RESULTS  
4.1 Convergence Maps and Cluster Catalogue  
4.2 Clusters Number Counts  
4.3 Mass-Temperature Relation  
5 DISCUSSION  
6 PROSPECTS FOR FUTURE SURVEYS  
6.1 σ₈ Measurements  
6.2 T* Measurements  
7 CONCLUSION