This thesis explores the personal, territorial/economic and spiritual networks of the Cantilupes and the Corbets, two families from different levels of the thirteenth century gentry. The Cantilupes were curiales; the Corbets were established Marchers who did not enter the king’s court. The study shows that each had a strong command of their respective power centres, yet the main branch of administrative Cantilupes deliberately pushed towards the Welsh March from King John’s reign onwards, while the Corbets, who were without the same networks of power and the consequent resources of these royal stewards, were also pushing for expansion within their own territory. This comparison illuminates the differences between these two families, neither of them great magnates per se, but both with strong links to the upper echelons of the aristocracy, and both with acquisitional and expansionist ambitions. The thesis identifies patterns of patronage and land-holding, and analyses their networks of relationships. Interaction between the two families is also considered, and the means by which family power and identity was represented and expressed are explored. The thesis concludes by identifying the common threads of a family strategy that, potentially, was followed by many thirteenth century gentry families of varying levels of social status. It considers the impact of the Welsh March on such strategies, and questions the ‘peripheral’ nature of such borderlands to those without Marcher territories.