Tensei Ouji wa Renkinjutsushi to Nari Koukoku Suru

Reborn as the third prince of a tiny and insignificant country, Hero happens to learn the forbidden-yet-powerful art of alchemy. Combined with his knowledge from modern-day Japan, Hero's abilities grow beyond what anyone in his world could fathom! With his newly-acquired powers, he’ll bring his country back from the verge of extinction...! A combination of modern-day knowledge and alchemy to turn a weak little country into a prosperous nation!

(Source: Square Enix)

Tensei Ouji wa Renkinjutsushi to Nari Koukoku Suru was published digitally in English as The Reincarnated Prince Becomes an Alchemist and Brings Prosperity to His Country by Square Enix through Manga UP!