The Oslo process began while the official, public negotiations that followed the 1991 Madrid peace conference were still going on. But after ten sessions, those talks had stalled again in the spring of 1993, this time over the status of Jerusalem, and it was becoming clear they weren't going anywhere. Madrid's failure increased interest among the highest level officials on both sides in the still-secret talks underway in Oslo.
Those talks, initially involving Israeli academics and mid-level Palestinian officials brought together by Norway's foreign minister, had gone much further than the Madrid talks. They culminated in September 1993 with announcement that letters of mutual recognition and a Declaration of Principles had been agreed to. The U.S. quickly moved in to take over sponsorship of the process, and the White House signing ceremony finalized the agreement.
Oslo's DOP separated the various issues that divided Israelis and Palestinians into two types: easy and hard. The theory was that the "easy" issues-such things as release of prisoners, economic cooperation, construction of Palestinian sea and airports, security considerations, etc.-would be dealt with first, during a five-year interim period. Discussion of the hard "final status" issues-including borders of a Palestinian state, settlements, Jerusalem and refugees-would not even begin until the third year, and their resolution would be delayed till the end of the interim period (which was eventually extended from five to seven years).