1971: Founded with L.S.R.G. support
Rugbyclub DIOK was founded on 28 March 1971 with support from the Leidsch Studenten Rugby Gezelschap.
In its 55th-anniversary account, the club describes its founders as a small group of rugby enthusiasts.
The lion emblem
DIOK’s badge carries a lion. The DIOK Lions charity page names the shared lion emblem and colours as one reason for forming a Lions club from the rugby club. The original reason for choosing the lion remains unconfirmed.