Several papers have primarily considered a female disadvantage in mortality as something to explain, considering a male disadvantage to be a "natural condition". Even if, due to biological reasons, shorter life expectancy among males has been demonstrated, other factors need to be involved to explain firstly the increasing, and then the decreasing, of the male relative disadvantage over the past century. The principal aim of this paper is to provide a clearer picture of the major age-class and cause-of-death contributions to male excess mortality in England and Wales from 1881 to 2011. Results indicate a clear shift in contributions to the male disadvantage from differences occurring during the first year of life to those occurring in ageing people, and from tuberculosis, respiratory diseases, external causes and perinatal and congenital conditions to neoplasms and circulatory diseases. In contrast, the narrowing of the gap since 1981 seems to be most closely related to the decrease in the male disadvantage in respiratory diseases and to the simultaneous increasing in the female disadvantage in old-age diseases. The most important novelty of this research relates to the method: instead of using ratios to investigate gender differences in health, we use decomposition methods.