Sea trials and modifications lasted more than a year, and once she entered active service in October 1899, the ship became the flagship of Prince Heinrich in I Squadron of the German "Heimatflotte" (Home Fleet). I Squadron was primarily occupied with training exercises throughout each year, and also made numerous trips to other European countries, particularly Great Britain and Sweden–Norway. In 1901, the ship was severely damaged after striking submerged rocks in the Baltic; the incident contributed to design changes in later German battleships to make them more resistant to underwater damage.