Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
List of ambassadors of Iceland to Yugoslavia
Table title:
List of ambassadors
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > # </th><th colspan=1 rowspan=1 > Name </th><th colspan=1 rowspan=1 > Appointment </th><th colspan=1 rowspan=1 > Termination of mission </th></tr>
<tr> <td colspan=1 rowspan=1 > 1 </td><td class="highlighted"  colspan=1 rowspan=1 > Helgi Pálson Briem </td><td class="highlighted"  colspan=1 rowspan=1 > 29 April 1953 </td><td class="highlighted"  colspan=1 rowspan=1 > 28 December 1960 </td></tr>
<tr> <td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > Pétur Thorsteinsson </td><td colspan=1 rowspan=1 > 28 December 1960 </td><td colspan=1 rowspan=1 > 3 December 1965 </td></tr>
<tr> <td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > Henrik Sveinsson Björnsson </td><td colspan=1 rowspan=1 > 3 December 1965 </td><td colspan=1 rowspan=1 > 6 September 1976 </td></tr>
<tr> <td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > Guðmundur Ívarsson Guðmundsson </td><td colspan=1 rowspan=1 > 6 September 1976 </td><td colspan=1 rowspan=1 > 9 November 1977 </td></tr>
<tr> <td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > Ingvi Sigurður Ingvarsson </td><td colspan=1 rowspan=1 > 9 November 1977 </td><td colspan=1 rowspan=1 > 21 March 1983 </td></tr>
<tr> <td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > Benedikt Sigurðsson Gröndal </td><td colspan=1 rowspan=1 > 21 March 1983 </td><td colspan=1 rowspan=1 > 4 February 1988 </td></tr>
<tr> <td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > Thordur Einarsson </td><td colspan=1 rowspan=1 > 4 February 1988 </td><td colspan=1 rowspan=1 > 1 February 1991 </td></tr>
</table>
Question:
What ambassador role and when did Helgi Pálson Briem serve?
Answer:
Helgi Pálson Briem was Ambassador of Iceland to Yugoslavia from 29 April 1953 to 28 December 1960.