Stephen V of Hungary
As soon as the Hungarians concluded peace with the Bohemians in March 1261, they, led by Stephen V of Hungary (co-king and Rostislav's brother-in-law) attacked Bulgaria. They first overran the Vidin province and forced "Tsar" Constantine Tikh to withdraw his troops from it. As a result of Hungary's action, Rostislav was restored to the position he had held prior to Constantine Tikh's attack on him in 1260. Whether further Bulgarian territory east of Vidin ("e.g.", Lom) was taken by the Hungarians or Rostislav is not known.