This is a rather unique set (!) of terra chiara vessels from Tunisia, northern Africa. They are so-called cooking pots. Both have a flaring rim which supports the lid. The lids of the vessels were also used as plates for eating.
As is sometimes the case with such sets, the smaller one exactly fits into the larger one, in order to facilitate storage and transport. For this principle see John W. Hayes, "Les sigillées orientales" in Évelyne Geny (ed., sous la direction de Pierre Lévêque et Jean-Paul Morel), Céramiques Hellénistiques et Romaines III (Besançon, Presses Universitaires Franc-Comtoises, 2001), 145-160, especially p. 158, fig. 6.
For a similar pot with lid in the museum of Bardo (Tunis), coming from Carthago and dating to the 4th-2nd century B.C. see Sabatino Moscati (ed.), The Phoenicians (Milano, Bompiani, 1988), p. 498.
It is rare to find a vessel together with its lid. But it is even much more rare to find a matching set of two of such pots, all in such good condition!
Circa 1st-3rd century C.E.
For the larger one: diameter 22 cm max., height including lid ca. 13.5 cm, ca. 8.5 cm without lid; for the smaller one: diameter of opening 17 cm, width of vessel 18.5 cm max., height including lid ca. 10 cm, ca. 6 cm without lid.
Dutch private collection, acquired in the 1990s from IADAA dealer Mieke Zilverberg, Amsterdam.
In excellent condition, with only a few minor scratches, pitting and other irregularities, as is common on all ancient pottery; some encrustation; very minor chip to the knob of the larger lid; some slight discolouration on the inside of the rim of the larger vessel that vaguely looks like a repair, but this is not the case, the discolouration was possibly caused by contact with the soil; on the bottom of the larger some one remnants of glue from a sticker or label which was once attached to it (only visible under black light).