Creator's Description: This paper aims to consider what the salient features of marriage among the Tibetan aristocracy were (especially regarding polyandry, matrilocal marriage, and hypogamy) through a systematic analysis of a sample of 324 matrimonial unions and to evidence crucial points related to the question of the internal and external boundaries of the aristocratic group. Varied sources have been used to reconstruct the genealogies and the marriages of many noble families from 1880 to 1959. British archives, including the lists or the Who's Who and the diaries and correspondence of the British officers present in Tibet during the period, provided most of the information. Data was also collected through interviews with around seventy members of the aristocracy. Biographies and autobiographies, written by Tibetan noblemen and women, provided further data for study. Matrimonial strategies appear to be at the same time a means of distinction and of renewal of the aristocratic group.