The Ottoman activities in Ethiopia proper preceded their invasion. They had supported the campaign of Imam Ahmad Gragn (which had begun in 1527), and following the Imam's reverse after the Battle of Jarta in 1542 they had sent him badly needed aid in the form of matchlockmen sent to Adal at a time when firearms in the region were rare: 10 cannons with artillery men, as well as many as 900 gunmen in 1542.[8] This support led to the destruction of almost all the Portuguese force under Christopher da Gama, and had Ahmad Gragn not dismissed these reinforcements soon afterwards, their help might have helped him to prevail at the decisive Battle of Wayna Daga.