Attempting to save the Empire enough money to allow Constantinople to remain the capital, Sergius traded the free bread citizens received in the city, a practice from older Roman times, as the government could no longer afford this,[11] an idea that didn't logically work. By 622, Sergius' abilities were well recognized by Heraclius. As a result, Heraclius assigned Sergius the care of both his son Theotokos and Constantinople.[12] In 626 during the absence of the Emperor's campaign against Sassanid Persia, the Avars and Sassanid Persians, aided by large number of allied Slavs, laid siege to Constantinople.