Abstract: Historic correspondence, in the form of letters, contains significant information of historic
figures such as their notes on the society, fluctuations in career, and life experiences. These letters can
help us expand knowledge beyond recorded historic events, supplement the details of historic literature,
and understand the complexity and versatility of these historic figures more comprehensively. However,
due to the limited scale of and access to historic correspondence, most correspondence research is stuck
on the level of individual letters. Different from previous researches, we, on the basis of our historical
correspondence network model, introduce two indicators, namely, topic relevance and topic similarity, to
explore the interpersonal/community relationships embedded in the individual ego-centric correspondence
network. We conduct experiments on the dataset of an individual letter collection, and correlate the
corresponding experimental results with certain historic events. This can be a valuable reference and guide
for researchers doing similar projects in future.

Key words:  Correspondence network, Ego-centric, Topic relevance, Correspondence relatedness network