Two strands of evidence can be used to map where Anglo-Saxon immigrants made their home in Britain: the distributions of Grubenhäuser and burials furnished with a distinctive suite of Germanic grave goods (which are referred to here as ‘Anglo-Saxon’ burials). Exactly who is buried within ‘Anglo-Saxon’ cemeteries is not altogether clear, as they may include both the immigrant population with their direct descendants and some native Britons (e.g. Arnold 1988; Hodges 1989; Härke 1990; 2002; Higham 1992; Scull 1995; Lucy 2000; Hamerow 2002; Hills 2003; 2007; 2009; 2011), and without major advances in scientific analysis we will never know whether some of those buried were ‘really just disguised Britons’ (Hills 1993, 15). Recent work on ancient DNA at Oakington, in Cambridgeshire, has established that both immigrants and natives were buried in this ‘Anglo-Saxon’ cemetery (Pitts 2016), but in order to determine how far Anglo-Saxon colonization extended across the landscape of eastern England we must rely upon more traditional archaeology. Of particular importance is the distribution of Grubenhäuser, as these distinctive structures had no precedent in late Roman Britain, suggesting that they were constructed and used by immigrant communities. Grubenhäuser are represented in the archaeological record as shallow(c.0.3–0.5m deep), sub-rectangular (c.3 by 4 m), steep-sided, and flat-bottomed pits above which was probably constructed a suspended wooden floor (e.g. Fig. 8.1; Tipper 2004). These distinctive structures have variously been called ‘huts’, ‘sunken huts’, ‘sunken featured buildings’, and ‘SFBs’, although all of these terms are problematic. The term ‘hut’ in particular led to an interpretation that they were crude hovels, whereas, now that examples have been reconstructed, we can see that they were substantial and impressive buildings (Fig. 8.2). The German term Grubenhäuser is used here specifically because it indicates that they were an alien formof architecture: although a number of Romano-British buildingswith sunken floors have been excavated, Tipper (2004, 7–11) has demonstrated that they represent an entirely different building tradition of cellars with revetted sides, entrance stairways, and floors associated with hearths and sunken storage jars (e.g. King Harry Lane in Verulamium: Stead and Rigby 1989).