Height is a well-established health indicator, which is determined by genetic and early environmental factors. This thesis investigates (i) contributions of a wide range of early environmental factors on growth at each life stage; (ii) whether the strength of the associations has changed between two generations; and (iii) whether social inequalities in height have narrowed. The study is based on the 1958 British Birth Cohort, all born between 3rd-9th March 1958, followed up at 7, 11, 16, 23, 33, and 41y, and their offspring. Fetal and childhood influences on growth of cohort members were examined using information on height at all ages simultaneously. Multivariate response models were used to explore these effects on growth trajectories, because these models take into account the fact that measurements on the same individual are correlated and also allow the comparison of the strength of associations across ages. Multilevel models were applied to compare the early life influences on childhood height between two generations taking account of correlations between cohort members and their offspring, and offspring themselves within families. Early life factors, including maternal smoking during pregnancy, social class, family size, household crowding, and parental divorce, had stronger effects on childhood height than on adult height. This suggests that children whose growth is adversely affected by unfavourable early conditions may catch up later. Childhood height is therefore a better indicator of early life circumstances than final adult height. However, the impact of some influences has changed over time, with some factors (i.e. maternal smoking, breastfeeding, maternal age at childbirth, social class, number of younger siblings, crowding, maternal education, and parental divorce) showing a decline in importance in a younger generation. Increases in height across generations, i.e. the secular trend, were due to a greater height gain in manual social class. This resulted in a narrowing of inequalities in height in more recently born British children.