Complex sentence: Despite its small size (According to the ISRP historian Lynch, the party never had more than 80 members) the ISRP is regarded by many Irish historians as a party of seminal importance in the early history of Irish socialism and republicanism.
Split into simpler sentences: Despite its small size (According to the ISRP historian Lynch, the party never had more than 80 members). The ISRP is regarded by many Irish historians as a party of seminal importance in the early history of Irish socialism and republicanism.