The nine walis were Sufi teachers who spread Islam and did all variety of powerful and unusual acts across Java. The histories of these men are not always clear. In fact, if you try to count all of them, you will end up with more than nine. Some sources say that there was more than one group of nine. In spite of the confusion, and some of the legends told about them, these were real men, and some of them such as Gunungjati or Kalijogo were important figures who helped create the Java--and the Indonesia--that we know today.
Here is an incomplete list of the Wali Songo. Most of them did their work in the mid-1500s:
Sunan Gunungjati worked at Demak and Banten, and was the founder of Cirebon.
Sunan Kudus, founder of Kudus, who is said to have originated the wayang golek.
Sunan Giri, who studied at Melaka, founded Islamic schools at Gresik, foretold rise of Mataram, spread Islam to Lombok, Sulawesi, and Maluku.
Sunan Kalijogo, active at Demark, advisor to Senopati, who revived the Garebeg procession, added Islamic stories to the wayang kulit repertory, and promoted the use of traditional rituals in a new Islamic context. The IAIN (Islamic Institute) in Yogyakarta today is named after him.
Sunan Muria, after whom Mount Muria is named
Sunan Maulana Malik Ibrahim
Sunan Ampel who did his work in Surabaya
Sunan Drajad who did his work in Lamongan
Sunan Bayat who did his work near Tembayat
(Sunan Kuning came much later, was named Susuhunan of Mataram by rebels in 1742, is remembered in Semarang)