George Washington
At the end of his second term, Washington retired for personal and political reasons, fatigued and disgusted with personal attacks, and to assure a truly contested presidential election could be held. He did not feel bound to a two-term limit, but his retirement ultimately set precedent. The two-term limit to the presidency was formalized with the 1951 adoption of the Twenty-second Amendment to the United States Constitution. Washington is often credited with setting the principal of a two-term presidency, but it was Thomas Jefferson who first refused to run for a third term on political grounds.
Alberto Fujimori
The 1993 constitution limited a presidency to two terms. Shortly after Fujimori began his second term, his supporters in Congress passed a law of "authentic interpretation" which effectively allowed him to run for another term in 2000. A 1998 effort to repeal this law by referendum failed. In late 1999, Fujimori announced that he would run for a third term. Peruvian electoral bodies, which were politically sympathetic to Fujimori, accepted his argument that the two-term restriction did not apply to him, as it was enacted while he was already in office.