Who they were
Saadi of Shiraz (c. 1210–1291/92 — the dates are uncertain) is among the most beloved Persian poets. He left Shiraz as a young man during the upheavals of the Khwarazmian and Mongol era and traveled for decades across the Islamic world, though scholars caution that the extent of the travels described in his works is partly literary self-fashioning.
What they did
He returned to Shiraz under the local Salghurid rulers and produced his two masterworks in successive years: the Bustan (The Orchard, in verse, 1257) and the Gulistan (The Rose Garden, in mixed prose and verse, 1258) — moral tales told with wit and worldly wisdom in a famously limpid style. His ghazals stand with the great Persian lyric tradition, and by standard assessment his prose style shaped Persian literary education for centuries.
Legacy
His celebrated verse on humankind as one body — its members created of one essence, so that when one member suffers the others cannot rest — is often linked to the United Nations: a Persian carpet bearing the verse, gifted by Iran, has hung in a meeting room at UN headquarters in New York since 2005 — the popular claim of an inscription at the entrance is a myth — and the US president Barack Obama quoted the verse in his 2009 Nowruz message. His tomb in Shiraz, the Saadieh, rebuilt in the mid-20th century, is a major monument, and in Iran his day is commemorated annually.