In November 1940, the Tegelen War Memorial was unveiled in memory of the victims of the sinking of the Dutch minesweeper Hr. Ms. Willem van Ewijck on September 8, 1939, in which 30 crew members lost their lives. That was just before the occupation of the Netherlands by the Germans, the Netherlands was still neutral. The Tegelen-born stoker 3rd class Henk Peters was one of the victims. The monument named Ik zal handhaven was probably the first war memorial for victims of World War II in the Netherlands. 
What the Germans presumably did not know: Ik zal handhaven (Je maintiendrai) was the motto of arms of William of Orange, the leader of the Dutch revolt against Spain. It marked the beginning of the Eighty Years’ War. The student Joe Russel from Tegelen was active in the resistance organization Aussenministerium , which was mainly concerned with helping students flee from Germany who were doing forced labor there and with distributing resistance newspapers. He was asked by the LO leader Ambrosius  from Venlo to organize the Venray district on the Venlo model. Initially Russel commuted back and forth between Venlo and Venray, but in March 1944 he settled permanently in that district. This included the North Brabant towns of Deurne and Helmond as sub-districts.
On May 1, 1944, the Sipo  raided Russell’s father’s business in Tegelen. Since his son could not be found, they took Russel Sr. hostage for ten days. Because of this incident, the latter decided to stop distributing underground magazines.
Joe Russel was present at the Weert raid but managed to escape. It took place on Wednesday, June 21, 1944. Almost the entire top of the Limburg LO was arrested there. On November 17, 1944, 46 men from Tegelen were deported to concentration camps. A plaque commemorating this event can be found on the wall of St. Martinus Church.
There are other places in Limburg where such plaques have been installed, such as in Beesel, Kessel and Roggel. 
From the Tegelen Encyclopedia Tegelenclopedie  we quote the following excerpts about the occupation period:
Between September 8, 1944 and March 1, 1945 Tegelen was not under Dutch administration. The administration of the municipality had then been taken over by the German Tegelen local group of the NSDAP, with local group leader Wilhelm Potthoff as the new mayor.
During the war, several clandestine periodicals appeared in Tegelen, including Christofoor, Moed en Vertrouwen, and ’t Snoekje, the first two of which were compiled elsewhere and printed in Tegelen, only ’t Snoekje was fully written by Tegelen waiter A. van Rooij. This paper, reproduced with a spirit duplicator , appeared daily until December 20, 1944, the day Van Rooij died. Remarkable was the role of the Steyl monastery leadership, which remained loyal to the Dutch bishops and refused to distribute NSB printed matter, and from 1944 onwards even housed people in hiding from the area.
The evacuation of Tegelen did not begin until February 11, 1945, when five hundred people were herded to Kaldenkirchen, from where they went on by train to Oldenzaal. A general evacuation did not come about at the last minute. 
Tegelen was liberated on March 1, 1945 during Operation Grenade. 
|All the fallen resistance people in Limburg|
Tegelen – 9 pers.
| - Tegelen - Dispatch Manager. He was born in Venlo and moved to Tegelen-Steyl in May 1943. He helped downed Allies (usually called pilots for simplicity’s sake) on their way home. He was arrested and was …|
wall: right, row 23-01
Gerardus Johann Willy
| - Engelandvaarders - Tegelen - Gerard Lemmen was a metalworker. The five friends Gerard Lemmen, Gerard Rooskens, Piet Saelmans, …|
wall: right, row 23-02
Petrus Nicolaas Andreas
| - The clergy - Aid to People in Hiding L.O. - People in hiding - Tegelen - Father Petrus Nicolaas Andreas Peters was a member of the L.O. Steyl and vicar. Pastor P.P. Windhausen, himself and three others from Steyl and …|
wall: right, row 22-01
| - Engelandvaarders - Tegelen - Electrician. The five friends Gerard Lemmen, Gerard Rooskens, Piet Saelmans, |
wall: right, row 22-02
| - Engelandvaarders - Tegelen - Cigar maker. The five friends Gerard Lemmen, Gerard Rooskens, Piet Saelmans, |
wall: right, row 21-06
| - Engelandvaarders - Tegelen - Reinier Schampers was a metalworker. The five friends Gerard Lemmen, Gerard Rooskens, |
wall: right, row 22-03
| - Engelandvaarders - Tegelen - Nico Scholten was a metal worker. The five friends Gerard Lemmen, Gerard Rooskens, |
wall: right, row 23-03
| - Communists & Sympathizers - Tegelen - Piet Sijbers was a soap dealer. He was considered a communist by the municipality of Tegelen and was therefore arrested by the occupying forces. But according to his brother Frits he was never …|
This person is not (yet?) listed on the walls of the chapel.04-27
| - People in hiding - The clergy - Tegelen - Petrus Paulus Windhausen (Catholic parish priest in Steyl-Tegelen), vicar P.N.A. Peters and three other people from Steyl and …|
wall: right, row 22-04