The Emir of Qatar has become the first head of state to visit Gaza since the Islamist group Hamas took power five years ago.
Sheik Hamad bin Khalifa al-Thani was greeted by Hamas Prime Minister Ismail Haniyeh who declared it a historic day for the enclave.
Israel has criticised the visit as "astounding", accusing Qatar of taking sides. Hamas has not renounced violence and doesn't recognise Israel's right to exist. It is considered a terrorist organisation in the West.
The Palestinian Authority of Hamas' rival Mahmoud Abbas said it hoped the trip would not undermine efforts to rebuild Palestinian unity.
Qatar has become a key source of revenue for Hamas. The visit is described as a humanitarian one, launching almost 200 million euros worth of reconstruction projects.
Gulf Arab states are trying to lure Hamas away from its alliance with Iran.