notions are relevant to Berkovich analytic geometry and to Drinfeld upper half-spaces. We also provide specific examples of compactifications which we generalize later. In Sect. 3, we sum up quickly what we need from Bruhat-Tits theory, including the existence of integral models for suitable bounded open subgroups; following the classical strategy, we first show how to construct a Euclidean building in the split case by gluing together Euclidean tilings, and then how to rely on Galois descent arguments for non-necessarily split groups. In Sect. 4, we finally introduce the maps that enable us to obtain compactifications of Bruhat-Tits buildings (these maps from buildings to analytifications of flag varieties have been previously defined by V. Berkovich in the split case); a variant of this embedding approach, close to Satake’s ideas using representation theory to compactify symmetric spaces, is also quickly presented. At last, Sect. 5 contains a new result, namely an intrinsic characterization of the image of the embedding we use, from Bruhat-Tits building to the analytification of the group; this gives a new description of the building in terms of multiplicative norms on the coordinate rings of the group.

[**Acknowledgements.**]{}  We warmly thank the organizers of the summer school “Berkovich 