the Treaty of Alliance in 1725 the Spanish crown recognised the Ostend
Company and thus gave it a legal sanction. The States therefore, after
some hesitation, became parties to a defensive alliance against Austria
and Spain that had been signed by France, England and Prussia at Hanover
in September, 1728. These groupings of the powers were of no long
duration. The emperor, fearing an invasion of the Belgian provinces,
first agreed to suspend the Ostend Company for seven years, and then, in
order to secure the assent of the maritime powers to the Pragmatic
Sanction, which guaranteed to his daughter, Maria Theresa, the
succession to the Austrian hereditary domains, he broke with Spain and
consented to suppress the Ostend Company altogether. The negotiations
which took place at this time are very involved and complicated, but
they ended in a revival of the old alliance between Austria and the
maritime powers against the two Bourbon monarchies of France and Spain.
This return to the old policy of William III was largely the work of
Slingelandt, who had become council-pensionary on July 27, 1727.

Simon van Slingelandt, with the able assistance of his brother-in-law
Francis Fagel, clerk of the States-General, was during the nine years in
which he directed the foreign policy of the Republic regarded as one of
the wisest and most trustworthy, as he was the most experienced
statesman of his time. His aim was, in co-operation with England, to
maintain by conciliatory and peaceful methods the balance of power. Lord
Chesterfield, at that time the British envoy at the Hague, had the
highest opinion of Slingelandt's powers; and the council-pensionary's
writings, more especially his _Pensees impartiales_, published in 1729,
show what a thorough grasp he had of the political situation.
Fortunately the most influential ministers in England and France, Robert
Walpole and Cardinal Fleury, were like-minded with him in being sincere
seekers after peace. The Treaty of Vienna (March 18,1731), which secured
the recognition by the powers of the Pragmatic Sanction, was largely his
work; and he was also successful in preventing the question of the
Polish succession, after the death of Augustus of Saxony in 1733, being
the cause of the outbreak of a European war. In domestic policy
Slingelandt, though profoundly dissatisfied with the condition of the
Republic, took no steps to interfere with the form of government. He saw
the defects of the stad