The Red Devils, chocolate or beer and the King, such is the typical answers given to the oft-asked question of what is still holding Belgium together. To these three symbols, two extra elements are often added: the debt and Brussels, the capital of the country and of the Flemish Region/Community, the French Community (politically but not constitutionally the Wallonia-Brussels Federation), the European Union (to be more specific, one of the three capitals, along with Strasbourg and Luxemburg), while being as well the seat of the Brussels Capital Region. Generally, the list of factors of unity in Belgium ends with this short list. Is it already too long, or on the contrary, is it really too short? This is the main question of this chapter. Paradoxically, although this question often arises, there are very few scientific writings analyzing it. To do so, this chapter will discuss six sets of factors: historical, identity, socio-economic, political, international and symbolic. Nonetheless, it is important to take into account that such enterprise seeks to be informative and not prescriptive. This chapter does not assume that Belgium should be united. There are several points of view about what Belgium should be, and this contribution merely wishes to nurture the political debate by conveying an original approach on six types of factors.