How did Philip II Augustus use the conflict between Henry II of England and Richard I?

Philip II Augustus skillfully exploited the internal tensions within the Plantagenet family to weaken their hold on French territories and expand the royal domain. He recognized the estrangement between Henry II and his son, the future Richard I, and used it to his advantage by fostering an alliance with Richard against the elder king.12

This strategy yielded significant political and territorial gains:

• Exploiting Estrangement: Philip encouraged the conflict between father and son, leading Richard to voluntarily perform homage to him in 1188.1
• Diplomatic Pressure: By fueling these divisions, Philip forced Henry II to make concessions, including the cession of Issoudun and Graçay and the renunciation of claims to suzerainty over Auvergne in the Treaty of Azay-le-Rideau (1189).1
• Strategic Opportunism: Following Henry's death, Philip continued to manipulate the succession and the rivalries between Richard and his brother John, eventually using John’s failure to appear at the French royal court as a pretext to confiscate his fiefs and conquer Normandy and other key provinces.12