1 INTRODUCTION  
2 DATA  
3 X-RAY PHOTOMETRY  
4 HOST GALAXY PHYSICAL PROPERTIES  
5 REDSHIFT EVOLUTION OF HMXB EMISSION  
6 METALLICITY DEPENDENCE OF HMXB EMISSION  
7 HMXB EMISSION FROM STRONG LYMAN-ALPHA EMITTERS  
8 CONTRIBUTION TO THE COSMIC X-RAY BACKGROUND  
9 CONCLUSIONS