  During its long-lasting history, the $\Lambda(1405)$ has become a benchmark
for our understanding of the $\rm SU(3)$ hadron dynamics. Starting with its
theoretical prediction and later experimental verification, until the most
recent debates on the existence of the second broad pole, it emerged as a
fruitful research area sparking many theoretical and experimental developments.
This review intends to provide the reader with the current status of research
on the $\Lambda(1405)$-resonance, reflecting on historical, experimental and
theoretical developments. A common database for experimental results and a
comparison of most recent theoretical approaches will be provided in the last
two parts of this manuscript.
