By July, the Austrian forces in Italy had retaken most of Venetia and were ready to launch an all-out attack on the Sardinian lines. At the Battle of Custoza, the Austrians broke through, forcing the Sardinians to retreat to Milan. Unwilling to continue the fight, Sardinia agreed to an armistice and promptly withdrew from Lombardy.
In late June 1848 the German National Assembly (Frankfurt Parliament) elected Archduke John of Austria as Regent of the Provisional German Empire (which was intended to replace the German Confederation). John—chosen because of his reputation both as a liberal and a loyal prince of the Imperial household—was effectively acting as viceroy for the Austrian Emperor at the time, but accepted the nomination on 5 July. After some back and forth between Vienna and Frankfurt, he resigned as viceroy later that month for his new position as head of the German government.in wikipedia
In early July 1848 forces of the Russian Empire crossed into the Principality of Moldavia, a vassal state of the Ottoman Empire, in order to prevent the establishment of a revolutionary government similar to that in Wallachia (which they would invade two months later). Russian military administration in Moldavia lasted until May 1849.in wikipedia
In late July 1848 Austrian Field Marshal Joseph Radetzky led 76,000 men against King Charles Albert of Sardinia, whose 75,000-strong Piedmontese line stretched from Mantua to Verona in Lombardy-Venetia. The Austrians attacked at Rivoli at dawn on the 22nd and by the 24th had gained control of the passes around the Mincio. The following day they broke through at Custoza and on the 27th at Volta Mantovana, breaking Piedmontese resistance and forcing them to retreat to Milan.in wikipedia