Forty years ago his parents were travelling when being attacked and never managed to return to other dwarves. They had the neccesary stuff to survive and went to the nearest hill, making it a home. 3 years and 5 months later he was born. When he aged 3 his father gave him a pickaxe resembling toy. When he was five he developed an interest in mining and ores. This resulted in his first pickaxe as gift from his father. When he was 8 he managed to break the harder stones and found his first ores. At age of twelve he was taught how to craft and be able to survive alone. At age of 16 his training ended and he parted ways with his parents, trying to fullfill their wish and return to the dwarven city.
But he got distracted along the way and started mining whole routes underground. Sometimes meeting wanderers hiding in caves. The last one he met, a dwarf made him think about his promise. He got interested in the outside world after surviving underground for over 10 years. This made him return to the actual world. His adventure resulted in him being shorter, have more muscles and good endurance, however this doesn't make him able to run fast or long. In fact, he is slower. He doesn't really have an idea of wealth and value.
