Ottoman Turks briefly occupiy the highland parts…
1540 CE to 1683 CE
In 1578 they try to expand into the highlands with the help of Bahr Negash Yisehaq, who had switched alliances due to power struggle, and by 1589 once again they are apparently compelled to withdraw their forces to the coast.
After this, the Ottomans abandon their ambitions to establish themselves on the highlands and will remain in the lowlands until they leave the region by 1872.