He obtained his secondary education at Prague, studied law at Heidelberg, and returned to Bulgaria for a career in journalism and politics.
Radoslavov joined the Liberal party, and, at the age of thirty, took office as minister of justice. He led the government from 1899 to 1901. It was a period marked by peasant discontent, to which Radoslavov responded with heavy military force. By the time he left office, his reputation for brutality was coupled with a reputation for corruption. The latter scarcely distinguished him in a notoriously unprincipled circle of peers. The actions and policies of Bulgaria's monarch, Prince Ferdinand, dominated affairs of state. In R. W. Seton-Watson's stinging phrase, Ferdinand manipulated parties, leaders, and politics by "his skill in calculating the psychological moment for driving each batch of swine from the trough of power."
Radoslavov was distinguished, however, by his pro-German and pro-Austrian views. In the early days of the Second Balkan War (June/July 1913), he publicly called on Ferdinand to break Bulgaria's longstanding tie to Russia. Friendly relations with Austria and Turkey, he maintained, were more appropriate for Bulgaria's territorial ambitions in the Balkans. The suggestion matched Ferdinand's own intentions. The monarch installed Radoslavov and an Austrophile Cabinet. Pro-Russian feeling remained strong in Bulgarian public life, but the common purpose of the monarch and the leader of the government neutralized it. Electoral failures made no difference. Radoslavov missed a majority in the election of December 1913; Ferdinand's support and the fragmentation of the opposition in the National Assembly (Sobranie) saved the day. Radoslavov shaped a narrow majority in March 1914 after a typically clouded Bulgarian election: his margin of support came from hastily enfranchised Moslems in territory just won in the Balkan Wars.
On the eve of World War I a loan from Austria and Germany marked Radoslavov's policy of rapprochement with the Central Powers. Formerly, Bulgaria's meager state treasury had been filled with the help of the French. Objections by political opponents were brushed aside. In mid-July Radoslavov declared the loan ratified after a raucous Sobranie meeting during which the minister-president had brandished a pistol and ignored cries for a roll call vote.
The outbreak of World War I placed Bulgaria in the position of being courted by both sides. Memories of the military and diplomatic defeats in the Second Balkan War were still fresh; Radoslavov and Ferdinand saw that the new conflict offered vast opportunities. The precise relationship between the monarch and his chief minister remains uncertain. Radoslavov's memoirs, on this issue as on most other controversies, are relentlessly uninformative. It seems likely that Ferdinand determined the direction of Bulgarian foreign policy; Radoslavov, as an influential adviser, implemented it. The two shared a sympathy for the Central Powers, but both were willing to take the Entente's offers seriously. While Radoslavov lacked diplomatic experience, he soon proved himself an adept negotiator.
In early August 1914, Austria began the bidding: Bulgaria's reward for joining the Central Powers was to be territory in Serbian Macedonia. Greece and Rumania quickly expressed their objections to such Bulgarian expansion. Together with Russia, they held Radoslavov's government to a course of neutrality. By late August, on the other hand, it was evident a tie between Bulgaria and the Entente would meet Serbian resistance. The Serbs had thrashed the Austrian invaders and sent them back across the Save and Drina. Belgrade saw no need to sacrifice its Macedonian holdings to entice Bulgaria to fight alongside Britain, France, and Russia.
Bulgaria's actions in the last months of 1914 leaned toward Berlin and Vienna. Radoslavov declared martial law and stifled pro-Russian demonstrations. Sofia permitted military personnel and supplies to pass through from the Central Powers to the Turks. Beyond that, Ferdinand and his chief minister would not go. Radoslavov, described by contemporaries as resembling "a maître d'hôtel," showed himself admirably equipped for the world of wartime diplomacy. He pointedly reminded the Austrians in late November 1914 that he was negotiating with the Entente. Such talks, he claimed, were needed to appease his domestic opponents. The implicit threat did not go unheard. By January 1915, Radoslavov obtained written pledges of territorial concessions from the Central Powers in Serbian Macedonia. Bulgaria pledged only to remain neutral. Radoslavov had hinted he would apply military pressure on Serbia by troops near the Serbian frontier. He quickly found "technical reasons" why this could not be done.
The Allied attack on the Dardanelles threatened to reverse Bulgaria's steady drift toward the Central Powers. But General von Falkenhayn underscored the need for Bulgarian aid in crushing Serbia and opening supply routes to the beleaguered Turks. Germany seized the diplomatic initiative from Austria, following which Radoslavov received urgent and generous offers. German victories on the eastern front removed Ferdinand's hesitations. The Gorlice breakthrough in early May 1915, the capture of the major Galician city of Lemberg in late June, and the headlong retreat of the Russian army eastward throughout the summer made a German victory in the entire war seem certain. By early September 1915, the Central Powers concluded a military convention and treaty of alliance with Radoslavov’s government. A Bulgaria large enough to dominate the Balkans was to emerge from the final peace settlement. In Silberstein's phrase, under Radoslavov's skilled leadership the Bulgarians "had run an expert race."
The invasion of Serbia (October/November 1915) brought hard fighting but culminated in triumph for the Central Powers. The acquisition of Macedonia temporarily quieted Radoslavov's domestic opponents, and the new year began well. Radoslavov's government even got Germany's consent to occupy Macedonian territory originally assigned to Austrian troops. But the obligations that came with an alliance to Germany soon exacted a toll. Berlin pressed Radoslavov's government to join in war against Rumania, dangling the Dobrudja as compensation. When Radoslavov agreed, he faced strong domestic opposition in the Sobranie. The political criticism sharpened when Germany used Bulgarian troops in operations outside the Dobrudja; and the army itself
began to show the strain when restive Bulgarian units found themselves crossing the Danube for an advance on Bucharest.By the close of 1916 new frictions were evident to cast doubt on Radoslavov's policy. German requisitioning detachments depleted Bulgaria's food reserves; seized for the Macedonian front, Bulgarian food went more often to Germany itself while Bulgaria was left hungry. Facing Salonika, the Bulgarian army felt weak and unnoticed, in no condition to deal with burgeoning enemy activity. The fall of Monastir in November 1916 caused little concern in Berlin, but seemed ominous when viewed from Sofia. Meanwhile, the Dobrudja, Bulgaria's reward for helping defeat Rumania, remained in German hands.
Radoslavov found himself taunted at home as a German mercenary. He pleaded his case personally at Berlin in early 1917 but returned empty-handed. Refusing to join Germany in declaring war on the United States had no effect on Berlin; and Radoslavov was too closely bound to an alliance with Germany to make moves for a separate peace with the Entente. A final winter made especially painful by widespread hunger set the stage for Radoslavov's departure. The Bucharest peace treaty between Rumania and the Central Powers (May 7, 1918) eliminated Bulgaria's last hopes for receiving the Dobrudja, thereby dooming Radoslavov's government. In June Ferdinand replaced him with the Ententophile Malinov.
Radoslavov's followers continued to dominate the Sobranie and to bolster Ferdinand's efforts to continue the war. It took the Macedonian debacle in mid-September and the armistice at the close of the month to sweep both Radoslavov and his monarch to exile in Berlin.
During the postwar period the Agrarian regime of Alexander Stamboliski tried Radoslavov in absentia and condemned him for maneuvering Bulgaria into the war. The fall of Stamboliski in 1923 led to efforts to amnesty the former minister-president, ill in Berlin. A bill allowing Radoslavov to come home passed finally in June 1929. It was too late. The ailing old leader died, still in Berlin, on October 21, 1929.