The 84-hour Operation Storm, a joint military and police operation, ended a Serb armed rebellion in August 1995 and liberated 10,400 square kilometres or 18.4 per cent of Croatia's territory. During the offensive, Knin was liberated on August 5 and President Tudjman hoisted a large Croatian flag at the local fortress to mark the conclusion of the operation.
During today's ceremonies, the Tudjman monument was unveiled by the incumbent president Kolinda Grabar-Kitarovic and Tudjman's son Miroslav.
Also, the programme included flights of MIG fighter jets and the firing of cannons as a military honor for Croatian soldiers killed during the operation and whose names were read out at the commemorative event at the fortress.
Apart from President Grabar-Kitarovic, also Parliament Speaker Josip Leko, Prime Minister Zoran Milanovic and other top officials as well as retired generals were present at the commemorative events on Wednesday morning.
Also in attendance were Opposition leader Tomislav Karamarko, prominent figures from the public life and famous athletes as well as a delegation of the "Mothers of Srebrenica" delegation.
Earlier in the morning the museum dedicated to Operation Storm was officially inaugurated.
A requiem mass follows after the fortress events.
Festivities including concerts of local pop and rock bands will take part in Knin and throughout Croatia on Wednesday afternoon.