If a family had a farm or a croft, it was normally inherited by the eldest son.
The other children had to seek position as farm hands or maids at bigger farms
in the surrounding neigbourhood.

To become a soldier was then an easy solution for a poor boy to get established
and make a living.

In the subsistence economy of the time, landowners where by law obliged to keep
soldiers and supply them with a croft and and a little piece of land to get a
crop for food and for to keep some animals. They also had to supply wood for
fire and fence-building and leaves as food compliment for the animals.
The soldier was able to keep a cow or two, a copule of pigs and some hens.
Greater farms could keep several soldiers and small ones had to go together
keep a single one. The army also payed the soldier a small wage in money.

In the army there was a need for different names on the soldiers.
All the soldier in a company had to have different names,
so there was no confusion who was adressed when giving orders.

Preferably the name should be short and easy to call out.
The problem was, though, that a lot of people shared the same names.
There were lots of Anderssons, Petterssons and Svenssons that enrolled,
so the army simply gave the soldiers new surnames.
The names also often followed the supplied crofts,
so all soldier in a certain croft normally got the same surname.
Many Soldier kept their soldiers name instead of their family name,
when they were dismissed.