Prince William and Prince Charles are both campaigning to save the environment by establishing different eco-initiatives but there was apparently a time when William engaged in a heated argument with his father over an environmental issue that the Duke of Cambridge staunchly fought.

According to an insider, William was at odds with his father when Charles refused to destroy the 1,200 artifacts from his ivory collection as some of these dated back to the time of his great-great-grandmother Queen Victoria. The Duke of Cambridge wanted his family to set an example as he was campaigning to put an end to the illegal wildlife trade.

But Charles turned down his son's request, which drew a frank exchange between the two heirs to the British throne. Insiders dished that Charles told his son his views were "naive" and then he proceeded to rebuke the comments William made in public.

As a young man, William had a temper that worsened his relationship with Charles. Royal insiders recalled that William used to challenge his father a lot.

Charles was also once asked to publicly comment on William's efforts for the environment. When the Prince of Wales refused to say anything, or even show a simple acknowledgement or praise, the public saw this as a competition between the father and son.

But royal editor Emily Andrews said that the past two years saw Charles and William dealing with each other better. Andrews said that Charles has been giving William a chance to share his inputs because he believes that they both have a "shared purpose" and duty.

The Prince of Wales also sees that he needs to prepare William for the long-term since his own reign as the king, after Queen Elizabeth, will be short. With Prince Harry, Meghan Markle and Prince Andrew out as senior royals, William will need all the help he can get from the remaining working royals.

Royal observers said that Harry uprooting his life in California with Meghan became a key factor in Charles and William's maturing relationship. Kate Middleton, the Duchess of Cambridge, also played a significant part in the healing of the tension between father and son as she has encouraged her children -- George, Charlotte and Louis -- spend more time with their gradfather, Charles, along with William.

According to reports, Charles  has been spending regular hours walking with the Cambridge family at their country estate, Anmer Hall, in January. Charles and William particularly enjoy identifying wildlife and birds with the children.