Sivusuvut

Sivusuvut are collateral lineages within a family tree, referring to branches that descend from a common ancestor but are not part of the direct line of descent. In genealogical work, sivusuvut help scholars map the broader family network beyond the principal line.

The concept stands in contrast to the pääsuku, or main lineage, which follows the direct line of succession from an ancestor to descendants. Sivusuvut include descendants of siblings, aunts and uncles, and cousins who form separate branches from the main line as families expand through marriage and migration.

Constructing sivusuvut involves tracing all known descendants of an ancestor and organizing them into branches tied to specific collateral lines. Researchers use parish records, civil registers, probate documents, census material, and genealogical databases to identify individuals and connect them to the common progenitor.

Sivusuvut are useful for understanding historical population structure, property inheritance, social networks, and demographic patterns. They also reveal how migration and marriage patterns created dispersed family nodes. However, documentation for collateral lines may be more fragmented than for the main line, and some branches remain incomplete.

Etymology: the Finnish term sivusuvut combines sivu (side) and suku (lineage or clan). In Finnish genealogical literature, sivusuvut is used to describe the offshoot branches of a family tree. See also pääsuku and haara-suvut as related concepts.