xvii.] Meanwhile Russia had secured the co-operation of Roumania by a convention signed on April 16, whereby the latter State granted a free passage through that Principality, and promised friendly treatment to the Muscovite troops.

The Czar in return pledged himself to "maintain and defend the actual integrity of Roumania[133]." The sequel will show how this promise was fulfilled.

For the present it seemed that the interests of the Principality were fully secured.

Accordingly Prince Charles (elder brother of the Prince Leopold of Hohenzollern, whose candidature for the Crown of Spain made so much stir in 1870) took the further step of abrogating the suzerainty of the Sultan over Roumania (June 3).
[Footnote 133: Hertslet, vol.iv.p.

2577.] Even before the declaration of independence Roumania had ventured on a few acts of war against Turkey; but the co-operation of her army, comprising 50,000 regulars and 70,000 National Guards, with that of Russia proved to be a knotty question.