Heathenry's deities are adopted from the pre-Christian belief systems found in the various societies of Germanic Europe; they include divinities like Týr, Odin, Thor, Frigg and Freyja from Scandinavian sources, Wōden, Thunor and Ēostre from Anglo-Saxon sources, and figures such as Nehalennia from continental sources. Some practitioners adopt the belief, taken from Norse mythology, that there are two sets of deities, the Æsir and the Vanir. Certain practitioners blend the different regions and times together, for instance using a mix of Old English and Old Norse names for the deities, while others keep them separate and only venerate deities from a particular region. Some groups focus their veneration on a particular deity; for instance, the Brotherhood of Wolves, a Czech Heathen group, center their worship on the deity Fenrir. Similarly, many practitioners in the U.S. adopt a particular patron deity for themselves, taking an oath of dedication to them known as "fulltruí", and describe themselves as that entity's devotee using terms such as "Thorsman" or "Odinsman".