His father was Dirk Lambrechtszoon, merchant and member of the town council of Schiedam, and organist of the church there.
He was accompanied on his adventurous journey by Cornelis Pauw (son of the Amsterdam mayor Reynier Pauw), Ernst Brinck, secretary, and Cornelis Sijms, both also sons of regents and Andries Suyderhoeff, who later replaced Brinck as secretary of the delegation, and Lambert Verhaer, who had been a goldsmith in Constantinople and was the only member of the group who had made the journey before.
[1] Haga laid the foundations of diplomatic relations and he erected numerous consular posts at the most important ports and trade-centra in the Ottoman Empire; Patras, Thessaloniki, Athens, Gallipoli, Smyrna, Aleppo, Sidon, Dairo, Tunis and Algiers.
The sultan also granted the Dutch several privileges, including exemption of certain taxes and limited autonomy within the empire.
His descendants added an epitaph to his grave, reading, amongst others Foris ac domi et de patria bene meritus fuit or He served his country well, both at home and abroad.