The beginning after the end
Ongoing | Turtleme,Fuyuki23 | 2000 released
Powerfull men (king) wakes up and find out he is a newborn baby in another world. He is intelligent and t trains when he is 6 months old, when he is 3yo he is thrown down the hill from bandits and find out a hidden Golem/Dragon. Gets lost in a forest and meets elf princess and when he is 9 gets sent back to parents. He is very strong mage and when he is an adventurer with his friend he begins training of knight with sword. Read up to season 2 - ends with 56 chapter
Tensei Shitara Slime Datta Ken