Land owned by the Palestinians before the Jews made it their homeland after the Holocaust in Europe.
4. 1947 – Proposed UN Partition Plan
Following the end of WWII, the newly formed United Nations proposed a plan that would grant 55 percent of historic Palestine to a Jewish state and 45 percent to a non-contiguous Arab one. Jerusalem would remain under international control.
Palestinians rejected the proposal because it stripped away much of the land that was under their control.
Bs"d
The land was not under control of the Arabs, it was under British control.
At the time, they owned 94 percent of historic Palestine and comprised 67 percent of the population.
Like I said, they didn't own it.
The mandate of Palestine was destined in the Balfour declaration to become a Jewish homeland.
Then the English chopped off almost 80% of that, and gave it to the Arabs, that became Trans-Jordan, the name later changed into Jordan.
Then they decided to split the remaining 20% between Jews and Arabs, so that the Jews would be getting almost nothing. The Jews accepted that, and the Arabs started a war to genocide all the Jews. The Jews won, and the Arabs lost some land, and Israel was established.
This plan was never implemented on the ground.
Because the Arabs refused it. The Jews agreed, the Arabs did not, that's why it was never implemented on the ground.