Detail from Simone Martini's fresco of the Life of St. Martin,
in the Cappella di San Martino, Lower Church of San Francesco, Assisi.
(I don't know exactly when the picture was painted, but Martini's dates
are 1284-1344.)
Note the tent-pole finials, each in the shape of a sphere on a short
stem. All the tents are decorated with vertical, dark-colored stripes,
with rows of colored triangles along the edges of the door and geometric
or heraldic patterns at the shoulder. Notice also that the main
guy-lines come from three-way "crow's-feet" attached through dark
grommets at the top of the decorative shoulder-strip. All the tents are
apparently circular, and one has a visible center-pole.
For the furniture buffs, the Roman Emperor Julian is sitting in a
(perhaps folding) throne in the form of a curved X-chair decorated with
gold lions, with his feet resting on a carved wooden box.
Thanks to Stephen Wyley, who found this picture at the Web Gallery of Art; thanks also to Emil Kren and Daniel Marx of the Web Gallery of Art, whose scan (above) I copied from their Web page on Simone Martini.