The "double-bell wedge tent", distinguished by having two vertical
center poles, no shoulder, and an oval (not rectangular) footprint,
is available from a number of commercial tentmakers, e.g. Panther
Pavilions, who describe it as "an extremely old design". However, I
haven't seen any solid evidence for its existence in Europe before
the late 15th century; this single tent appears in the upper left of an illustration
from the late 15th-century Das Mittelalterliche
Hausbuch, among dozens of shouldered tents, both circular and oval.