Tea Bowl known as "Jirobo", Raku Ware, Kuro-raku Type

Raku ware, one of the most important ceramic styles of the Momoyama period (1573-1615), is said to have started in Kyoto with the tile maker, Chojiro, under the direction of the tea master Sen no Rikyu (known also as Soeki, 1521-91), who sought to create a new style of bowl for drinking matcha (powdered green tea). This black Raku bowl, known as Soeki nari ("Soeki shape," referring to a style favored by Rikyu), was formed by hand into a simple half cylinder with no artifices or pattern on its surface. The slightly top-heavy thick rim gently turns inwards, while the body is softly squeezed in and generously rounded out near the foot. Though simple in appearance, the subtle variations give this bowl its sublimated form, which befits Rikyu's introspective style of tea.
On the lid of the inner box, which accompanies this bowl, is an inscription written in red lacquer: "Jirobo. Genpaku. (colophon)." On the back of this lid is a longer inscription by Senso Soshitsu (1622-97), a tea master of the Sen family and the youngest son of Genpaku Sotan (1578-1658), which states that Sotan received this tea bowl from his grandfather Sen no Rikyu.