During his travels in Flanders, which at that time belonged to Spain, he had grieved to see how unhappy the people were made by the Duke of Alva, the State minister of Philip the Second of Spain. Philip did not love his Flemish subjects at all; they were mostly Protestants, and he wanted to take their liberty from them and force them to become Roman Catholics. And when they began to rebel against his unjust treatment, he sent the cruel Duke of Alva to them, having first told him that he might do whatever he liked with them.
Alva arrived in Brussels, and began by arresting and imprisoning the Counts Egmont and Horn, two noble-minded men, who, after trying in vain to make peace between the king and the Belgians, had taken the part of the Protestants from a love of justice and mercy. Count Egmont had helped Philip to win the great battle of St. Quentin over the French, but he was compassionate as well as brave, and Philip was so afraid that he would be too kind to the people of Belgium that he advised Alva secretly to get rid of him.
Alva kept the Counts in prison in Ghent for nine months, and then had them carried to Brussels and beheaded, on the 4th of June, 1568, on a scaffold raised on one of the principal squares in the city. They died with courage, martyrs for the liberty of Flanders, but their execution was a cruel injustice, and the people were nearly frantic with grief when the bloody deed was done. Alva remained in Flanders more than four years, and is said to have caused eighteen thousand Protestants to be beheaded during that time. Then Holland rose in revolt; the Prince of Orange was made stadtholder, and Alva, seeing that his day was over, went back to Spain, where he must have been very unhappy when he thought over all his wickedness. The Protestants in Germany fared very little better than those in Flanders, for when the Emperor Rudolf the Second began to reign, he forbade them to worship according to their faith. Sidney was sent on an embassy to Rudolf, and did all he could whilst he was in Germany to humble Spain.
The Flemings asked Elizabeth to be their queen; this she would not agree to, but she sent them some troops and some money, and Sidney implored her to let him take the command in the enterprise, he wanted so much to be of service to his fellow-men, and to deliver those who were unjustly treated from their oppressors. The queen declared, however, that she could not spare him from her Court, and he was obliged to wait patiently a little longer. Meanwhile he took part in the amusements of the Court, the jousts and the royal progresses from place to place, which were always attended with great show. To these must be added the masques, and the first time Sir Philip distinguished himself as an author was by writing a masque, entitled "The Lady of May," which was performed before the queen at Wanstead in Essex. Sidney was the patron of artists, musicians, and authors; he was a kind and sincere friend of the poet Spenser, who had originally been brought from his home in Ireland to the English Court by Sir Walter Raleigh.
Weary at last of remaining inactive, Sidney planned, without the queen's knowledge, an expedition to America, in which he was to be joined by the bold navigator, Sir Francis Drake. He had arrived at Plymouth, whence the ships were to start, when Elizabeth, having gained information of the projected voyage, sent messengers with letters to Sidney, in which she desired him not to sail, and threatened to stay the whole fleet if he did not obey her.
Sir Philip, already on the alert, contrived to intercept the messengers; their letters were taken from them by two soldiers disguised as sailors. The queen, finding threats useless, then sent a positive royal command to her favourite, which he was bound out of duty to his sovereign to obey, and thus he was fated never to see the beautiful new land in the west, with its growth of gorgeous flowers and rich fruits, its giant trees, and its bright-coloured birds, its wonderful landscapes, the beauty of which far exceeded the ideal formed of them.
Elizabeth's displeasure did not last long. It was the high esteem she held him in that made her so loth to let him quit England, and she was not offended with him when he had the courage to write her a letter in which he entreated her not to marry the Duke of Alençon, now Duke of Anjou, and pointed out the trouble such a union might bring upon England. The queen wisely followed his advice, and gave up all idea of a marriage which her subjects had very much disliked.
Sir Philip, one day in the tilt-yard, had a dispute with Lord Oxford, in which both were to blame, but Lord Oxford the more so of the two. This caused Sidney to withdraw for a time from Court, and retire to a house he had at Wilton, where he wrote "The Arcadia," a pastoral romance, and some other works, which gained him the fame of a poet. He did not mean "The Arcadia" to be published, nor did it appear in print until after his death. He wrote it to afford pleasure to his sister Mary, and sent to her each part of it as he completed it.
A time came when the Flemings were again reduced to a state of extreme wretchedness. The great and good stadtholder was basely murdered, and the Spanish troops were making rapid progress through the country. So they asked Elizabeth again to be their queen and to send them succour. She refused the crown a second time, but agreed to help the Flemings with troops on condition that the towns of Flushing and Brille should be placed in her hands. And Sidney, to his great joy, was appointed governor of Flushing, whither he went in November, 1585. The good Count Maurice of Nassau received him as a brother, and he was made general of all the forces, English and Dutch, in the town. Soon he had to welcome there his uncle, the Earl of Leicester, who, by the favour of Elizabeth, was entrusted with the command of the army.
For some time Sidney was obliged to remain inactive, but in the year 1586 he and Count Maurice surprised Axel, a town on the way to Antwerp, and the strongest place held by the Spaniards in the Netherlands. Here he kept his soldiers in the strictest order. When they were marching they were enjoined to be silent, and a band of the choicest among them was stationed in the market-place for the security of the town.